Adjustment: Coping, Reconstruction of Goals, and Causal Attributions

In the course of the selection process, adolescents may attain the goals to which they
were aiming. However, this is not always the case. In many situations, adolescents fail
to reach their goals or do not succeed to the extent they expected. Young people may
also face unexpected events that endanger some important aspects of their future lives.
When adolescents face problems in goal attainment, they need to adjust some of their
previous goals, cognitions, or behaviors (Figure 4.1). This adjustment process has been
described in terms of many psychological mechanisms (Table 4.1).
Coping
When adolescents face problems in goal attainment, they try to find new ways of dealing
with them, to avoid the difficult situation, or to avoid related information. These
kinds of efforts have been described previously in terms of coping strategies (Folkman,
Lazarus, Pimley, & Novacek, 1987). There are several ways to conceptualize coping.
According to Seiffge-Krenke (1993), for example, functional coping refers to efforts to
manage a problem by actively seeking support, undertaking concrete actions to solve a
problem, or reflecting on possible solutions. A dysfunctional coping includes withdrawing
from or denying the existence of the problem, avoiding active seeking of solutions,
and attempting to regulate the emotions (Seiffge-Krenke, 1993). Understandably, the
characteristics of the situation are important in the kind of coping an individual chooses
to use. For example, effective coping in changeable situations consists of a greater use
of problem-focused coping, whereas in an unchangeable situation effective coping involves
a greater use of emotion-focused coping (Compas, Banez, Malcarne, & Worsham,
1991; Folkman et al., 1987). Consistent with this proposition, Blanchard-Fields,
Jahnke, and Camp (1995) found that the use of problem-focused coping decreased,
whereas passive-dependent coping increased, in use with greater emotional salience.
92 Socialization and Self-Development
Research on coping shares similarities with research on strategy construction. Because
strategies are typically described as a way to attain a goal, they are here summarized
under the selection process. In turn, coping is often described as a way to deal
with goal nonattainment or with an unexpected event, and therefore it is discussed under
adjustment.
Goal Reconstruction
One further way for an adolescent to adjust to the negative outcomes he or she is facing
is to reconstruct personal goals. When people fail to actualize their goals for a specific
developmental trajectory, they are likely to modify their previous goals or to disengage
from them and engage in new kinds of goals as a part of accommodative strategies
(Brandtstädter & Renner, 1990). Doing this reconstruction helps the adolescent, after
a failure, to keep motivated, stay on a realistic level of functioning, and maintain positive
developmental perspectives when facing the next challenging life situation.
Goal reconstruction may lead to either positive or negative developmental changes.
For example, not succeeding in a particular sport may lead to a decision of trying another
kind of sport, which, in the long run, may result in a person’s finding a lifelong
hobby. In turn, having problems at school may lead to increasing interest in social activities
with peers, which may further increase low achievement. Goal reconstruction
on the basis of feedback from goal attainment is one key mechanism of motivational
development (Nurmi, Salmela-Aro, & Koivisto, 2002).
Causal Attributions
One mechanism that plays an important role in the adjustment to a failure in goal attainment
is an adolescent’s interpretation of events afterward. According to Weiner
(1986), after the event is interpreted as success or failure, an individual begins to
search for the possible reasons for this event. Such causal attributions typically refer to
one’s own effort, abilities, or skills; alternatively, they refer to the situation, other people,
or luck.
Most people apply self-protecting causal attributions in their efforts to deal with
negative outcomes in particular (Taylor & Brown, 1988; Zuckerman, 1979); that is, they
take credit for success but blame other people and situational factors for failure. The
function of this defensive thinking is to cope with negative feedback concerning their
self. Lack of such self-protective attributional bias has been shown to increase the likelihood
of depressive symptoms. The problem with the use of attributional bias is that it
leads to behavioral patterns that do not promote high effort in challenging situations
(Berglas & Jones, 1978).
An alternative approach to causal attributions is to conceptualize them from the
point of how functional they are for individual behavior. For example, Glaskow, Dornbusch,
Troyer, Steinberg, and Ritter (1997) suggested that dysfunctional attributional
style implies lack of faith in one’s performance capacities and a reluctance to assume
responsibility for one’s behavior and the outcomes it may generate. Their definition of
dysfunctional causal attribution included references to luck, teacher bias, task difficulty
for either success and failure, and lack of ability in response to failure. Functional
causal attributions refer to ability and effort after success, and effort attribution for a
failure.
Channeling, Selection, Adjustment, and Reflection 93
Reflection: Identity, Narratives, and Self-Concept
One psychological mechanism that plays a particularly important role during adolescence
is the way in which individuals perceive and reflect their individual characteristics,
behavioral outcomes, and social positions as a way to construct self-concept and
identity (Figure 4.1; Erikson, 1959; Harter, 1990). Three different conceptualizations
that have been used to describe this self-reflection process (Table 4.1) are discussed in
the next sections.
Identity
The ways in which an adolescent perceives him- or herself across time and space have
been described as identity (Baumeister & Muraven, 1996; van Hoof, 1999). One major
assumption of the original identity theory was that the particular social position or the
role the adolescent has adopted has consequences for his or her identity (Erikson,
1959). During adolescence, individuals explore different alternatives and end up in specific
adult roles. Perceiving oneself then in a particular role helps an individual to construct
an identity of who he or she is (Baumeister & Muraven, 1996; van Hoof, 1999).
Although identity, by definition, refers to the self-structures of an individual, the
vast majority of research in the field has relied on Marcia’s (1980) identity status paradigm,
which focuses on the processes that are assumed to lead to identity formation
rather than identity contents per se. Marcia originally operationalized Erikson’s (1959)
theory of identity formation in terms of four identity statuses. These were defined in
terms of the presence and absence of crises and commitment related to important life
decisions: identity diffusion (no current crisis or commitment); moratorium (current
crisis, no commitment); foreclosure (commitment, no apparent former crisis); and identity
achievement (commitment, previous crisis resolved).
Narratives
Individuals also construct narratives and tell stories about themselves as a way to create
an identity (McAdams, 1999). Because one main feature of human cognition is that
its contents can be shared by language, telling stories is an important means to increase
self-coherence, to support positive self-concept and high self-esteem, to relate one’s
identity to those of significant others, and to create prototypic identity narratives as a
member of a particular culture.
According to McAdams (1999), it is on the brink of adulthood that a person begins
to construe his or her life in narrative terms. The implicit goal of this is to create an internalized
story of the self that binds together the reconstructed past, perceived present,
and anticipated future in a way that confers upon life a sense of unity and purpose.
Although identity narratives vary in regard to content and structural features, agency
and communion are their typical themes, and they are often situated to a specific moral
or ideological setting (McAdams, 1999).
Self-Concept and Self-Esteem
Adolescents receive a substantial amount of feedback concerning their skills and competencies
during selection and adjustment processes. For example, how well an adolescent
is doing at school and the kinds of feedback he or she receives from peers and
94 Socialization and Self-Development
parents have consequences for what a person thinks about him- or herself (Harter,
1990). This self-concept has been among the most popular research fields in adolescent
psychology.
Although the concept of self has been expanded to refer to a wide variety of mechanisms,
the definition of self-concept is straightforward: It refers to relatively stable
schemata of oneself that are generalized to the extent that they refer to an individual’s
view of him- or herself across different situations. A person has a self-concept to the extent
that he or she has a coherent structure within which the multitude of self-relevant
thoughts and feelings achieve organization (Nowalk, Tesser, Vallacher, & Borkowski,
2000). By contrast, self-esteem is typically defined as the ways in which individuals evaluate
themselves according to normative or self-related standards. For example, positive
self-esteem might be assumed, by definition, to be caused by having more success than
expected, and negative self-esteem stems from having less success than expected.
CODEVELOPMENT: PARENTS AND PEERS
Although socialization and self-development, as evidenced in channeling, selection,
adjustment, and self-reflection processes, are often described as an individual development,
they are closely embedded in the adolescent’s interpersonal relationships (Nurmi,
2001). When thinking about their future life and related decisions, young people often
negotiate with, ask advice from, or reject information given by their parents and teachers.
Similarly, they model their peers and discuss their future lives with their friends
(Figure 4.2).
Three topics are particularly interesting in this context. First, to what extent is adolescent
socialization directed by parents, or do the outcomes of the adolescent socialization
activate certain kinds of parenting? Second, to what extent are adolescents influenced
by their peers, or do they rather select a peer group according to their own
interests and characteristics? Third, how are adolescents’ relationships to their parents
and peers related in the process of socialization into adulthood?
Adolescents and Parents: Cause or Effect?
Parent-adolescent relationships have been among the most examined topics in adolescent
development (Steinberg, 2001). Although family relationships have been theoretically
conceptualized as bidirectional interaction between the adolescent and his or her
parent (Bell, 1979; Lerner, 1982), empirical researchers seem to make a strong presumption
that it is parenting that influences adolescent development (Crouter, Mac-
Dermid, McHale, & Perry-Jenkins, 1990; Jacobson & Crockett, 2000). This seems to be
the case even for most recent research even though many researchers have challenged
this view and suggested that children also impact their parents’ child-rearing patterns
(Harris, 1995; Kerr, Stattin, Biesecker, & Fedder-Wreder, in press; Lerner, 1982; Lerner
& Spanier, 1978).
This issue of the extent to which parents’ attitudes, behaviors, and child-rearing patterns
influence their adolescents’ development, or whether it is children’s thinking and
behaviors that have an impact on their mothers’ and fathers’ parenting, is of key im-
Codevelopment: Parents and Peers 95
portance for this chapter. On the one hand, there are good reasons to assume that parents
influence the ways in which their adolescent children deal with the transition into
adulthood. There are at least three possible ways: First, parents may direct the development
of their children’s interests, goals, and values by communicating expectations
and setting normative standards; second, they may influence the ways in which their
adolescent child deals with various developmental demands by acting as role models
and providing tutoring; and finally, they may contribute to the ways in which adolescents
evaluate their success in dealing with these demands by providing support and
feedback (Nurmi, 1991). On the other hand, the adolescent’s success in dealing with the
key demands of his or her age-graded environments may well influence his or her parents’
expectations concerning their child’s future; adolescents’ competencies and coping
skills may evoke the use of certain parenting styles among the parents; and adolescents’
behavior may cause extra stress for parents, which then influence their thinking,
behavior, and even well-being (Figure 4.2).
Adolescents and Peers: Selection or Causation?
Aside from parents, peers and friends are involved in the ways in which adolescents deal
with the transition into adulthood (McGuire et al., 1999). Adolescents in a particular
peer group exhibit many similarities compared with adolescents in other groups. Such
homophily of the peer groups has been reported in many characteristics, such as aspirations
(Kandel, 1978), school work (Cohen, 1977), and problem behavior (Urberg,
Degirmenciogly, & Pilgrim, 1997). Two major mechanisms have been suggested to be
responsible for this homophily. First, peer groups may be important socialization
agents in adolescents’ development. In this case, adolescents become similar to their
peers because peers provide role models, feedback, and a platform for social comparisons
(Ryan, 2001). Second, adolescents may select peer groups having members who
share similar characteristics and interests with those they have themselves, or they may
leave groups that do not fit with their characteristics or motivation (Cohen, 1977).
Overall, selection and socialization into peer groups might be assumed to play an important
role in the ways in which adolescents deal with the transition into adulthood
(Figure 4.2).
Parents or Peers
Starting from early adolescence, children spend increasing amounts of time with their
peers both at school and after school (Larson & Richards, 1991), whereas they spend
less time with their parents (Collins & Russell, 1991). Some researchers have suggested
that children’s decreasing closeness to their parents is associated with their increased
orientation toward the peers. For example, Steinberg and Silverberg (1986) suggested
that the transition from childhood to adolescence is marked more by a trading of dependency
on parents for dependency on peers rather than a straightforward growth in
autonomy.
Parents and peers play different roles in individuals’ attempts to negotiate their ways
through adolescence. For example, Tao Hunter (1985) found that adolescents discussed
96 Socialization and Self-Development
with their parents particularly topics that related to adolescents’ social and economic
functioning in adulthood (i.e., academic, vocational, and social-ethical issues). By contrast,
they discussed with their friends particularly issues concerning interpersonal relations.
Another important issue is the extent to which adolescents’ relationships with
their parents and peers are associated. Fuligni and Eccles (1993) found that adolescents
who perceived high parental strictness and little opportunity for decision making were
higher in extreme peer orientation. In the following literature review I also examine what
is known about the role of parents and peers in adolescents’ socialization to adulthood.
RESEARCH ON SOCIALIZATION INTO ADULTHOOD
Earlier in this chapter, adolescent development into adulthood was described in terms
of four processes (Table 4.1). In the following sections I review the research on what we
know about the channeling, selection, adjustment, and reflection processes among
adolescents. For each process, the research on the nature of the processes, the developmental
changes, major antecedents and consequences, and the role of family and peers
are reviewed.
Channeling: Anticipations of Developmental Tasks and Transitions
Age-graded developmental tasks, role transitions, and institutional tracks were expected
to channel the ways in which adolescents direct their future development and select
their environments. Previous research supports this by showing that adolescents
have relatively detailed conceptions of their age-related developmental environments
(i.e., the timing of a variety of developmental tasks, role transitions, turning points, and
institutional tracks; Crockett & Bingham, 2000; Nurmi, 1989b). They also anticipate
their future lives as a sequence of transitions in which school completion is followed by
job entry, and then by marriage and parenthood. Moreover, their anticipations of the
major turning points is in accordance with the statistics of the median age at which individuals
go through these transitions in a particular society (Crockett & Bingham,
2000; Nurmi, Poole, & Kalakoski, 1996). This is not surprising because the cognitive
ability to make such estimations has been shown to develop well before the adolescent
years, by the age of 8 to 9 years (Friedman, 2000).
Research on how far into the future adolescents’ thinking and personal goals extend
gives a similar view. Nurmi (1989b, 1991), for example, showed that young people’s
thinking about the future extends to the end of the second and to the beginning of the
third decade of life: Adolescents expected their education-related goals to be actualized,
on average, at about the age of 18 to 19, occupation-related goals to be actualized
at the age of 22 to 23, and goals related to family at the age of 25 to 26. Adolescents’ life
course anticipations are also predictive of their subsequent life course events, particularly
in the family domain (Hogan, 1985).
Research has also shown gender differences in the life span anticipations. Girls tend
to anticipate forming a partnership, establishing a family, and having children earlier
than do boys (Malmberg, 1996), which again is in accordance with the statistics.
Research On Socialization into Adulthood 97
Among girls, the anticipations of the timing of educational and occupational transition
are closely connected to the anticipations of family formation (Crockett & Bingham,
2000). This finding is thought to reflect the fact that girls take into account the role conflicts
of these two domains more than boys do (Hogan, 1985).
The Role of Family
Family characteristics are associated with adolescents’ anticipations of their life span
transitions. For example, high parental education contributes to a later expected age
for all major transitions (Crockett & Bingham, 2000; Hogan, 1985). Similarly, adolescents
who have grown up in homes of lower socioeconomic standing expect earlier
youth-to-adult transitions. In addition, parents’ values are associated with their children’s
expectations: parents who have liberated sex-role attitudes have daughters who
expect to leave the parental household earlier than do the daughters of parents with
more conservative attitudes (Hogan, 1985).
Moreover, parents’ views of their adolescent child’s future transitions contribute to
the child’s future life. Hogan (1985) found in a longitudinal study that mothers’ educational
aspirations for their daughters predicted the timing of the daughters’ marital
transitions. Moreover, daughters of mothers who emphasized traditional sex roles were
more likely to marry as adolescents compared with other young women. By contrast,
daughters of mothers who emphasized the importance of career-preparatory education
tend to delay marriage and family.
Selection
Goal Construction
One mechanism that plays an important role in how an adolescent directs his or her development
and selects from a variety of environments is the kind of personal goals he
or she constructs. Such goals are important, because they help the young person to
move to a direction that would satisfy his or her personal motivation.
Transitions and Institutional Tracks One of the key assumptions of this chapter is that
adolescents construct their goals by comparing their individual motives to the opportunity
space created by their age-graded sociocultural environments. When adolescents
are asked about their future hopes and interests, they typically report topics that focus
on their personal future lives, such as education, occupation, family, leisure activities,
travel, and self-related issues (Nurmi, 1991; Salmela-Aro, 2001). It is interesting to note
that there is little variation across societies and cultures in such hopes and interests (for
a review, see Nurmi, 1991). During adolescence, individuals become increasingly interested
in future occupation, education, and family (Nurmi, 1989b). By contrast, adolescents’
interest in leisure activities decreases with age. The majority of the research on
developmental changes is based on age-group comparisons, although similar results
have been found in longitudinal studies (Nurmi, 1989b).
These results are in accordance with the life span theory of adolescent development
(Nurmi, 1991, 1993): A substantial proportion of adolescents’ future hopes and interests
focus on the major developmental tasks of this period. The finding that ado-
98 Socialization and Self-Development
lescents become increasingly interested in these topics with age may reflect the fact
that as the transitions come closer, they increasingly motivate adolescents’ thinking
(Nurmi, 1989a).
Young people not only construct goals that are in accordance with age-graded developmental
tasks and role transitions, but they also continuously reconstruct their
personal goals to match the specific stages of a particular transition they are experiencing.
For example, Salmela-Aro et al. (2000) showed that women who were facing a
transition to parenthood not only had goals that reflected this particular transition
overall but also reconstructed their goals to match with the specific stages of this transition:
Womens’ personal goals changed from achievement-related topics to pregnancy,
then to the birth of a child, and finally to taking care of the child and motherhood.
Moreover, Heckhausen and Tomasik (2002) found that vocational goals become more
sober and less glorious when the actual vocational transition moves closer.
A variety of institutional transitions and tracks also provide a basis for adolescents’
future-oriented goals. For instance, Klaczynski and Reese (1991) found that collegepreparatory
high school students held more career-oriented values and educational
goals, and projected their future goals further in the future, compared with vocational
school students. By contrast, vocational school students’ goals focused more on preparation
for adulthood and attainment of adult status than did those of college-preparatory
high school students. Similar results have been found for the interpersonal domain of
life. Salmela-Aro and Nurmi (1997) found that young adults’ life situation, such as being
married and having children, predicted their subsequent family-related goals. By
contrast, being single predicted turning to self-focused, existential goals.
Consequences Individual motivation and personal goals were assumed to play an important
role in the ways in which adolescents select their future environments and direct
their lives. Along this assumption, Schoon and Parsons (2002) found that adolescents’
aspirations at the age of 16 predicted their occupational aspirations during
young adulthood. Moreover, Nurmi et al. (2002) found that the more young adults emphasized
the importance of work-related goals and the more they thought they progressed
in the achievement of such goals, the more likely they were to find work that was
commensurate with their education and the less likely they were to be unemployed after
graduation. Furthermore, concrete college goals have also been found to predict
subsequent college attendance (Pimentel, 1996). Similarly, young adults’ family-related
goals predict their subsequent moving toward marriage or living in cohabitation relationships
(Salmela-Aro & Nurmi, 1997), as well as the actual age of cohabitation and
marriage (Pimentel, 1996). By contrast, young adults’ self-focused, existential types of
goals have been shown to predict subsequent negative life events, such as breaking up
of an intimate relationship.
Optimism and Control Beliefs In order to be active agents in the selection of their future
developmental trajectories, adolescents’ personal goals need to be evidenced in
their positive thinking about the future and belief in personal control. The research suggests
not only that a majority of adolescents show much interest in their future but also
that they are relatively optimistic about it and believe in their personal control (e.g.,
Research On Socialization into Adulthood 99
Brown & Larson, 2002; Nurmi, 1989a). Moreover, adolescents construct the view of
their personal future in ways that support their optimism. For example, they do consider
negative life events, such as divorce (Blinn & Pike, 1989), alcoholism, and unemployment
(Malmberg & Norrgård, 1999), to be less likely in their own future life than
in that of other people.
In addition, adolescents’ beliefs concerning the future become more internal and
optimistic with age (Nurmi, 1989a). However, present institutional environments are
associated with the ways in which adolescents attribute causes for their behavioral outcomes.
For example, Klaczynski and Reese (1991) found that college-preparatory high
school students made more internal attributions for positive educational outcomes
than did vocational school students. Moreover, Malmberg and Trempala (1998) showed
that vocational school students were less optimistic about their success in the future
than were secondary school students.
Adolescents’ Fears Adolescents also have fears and worries about their future that are
typically concerned with three major topics (Nurmi, 1991). First, young people typically
report concerns related to dealing with normative developmental tasks, such as
becoming unemployed, failing at school, and facing a divorce (Solantaus, 1987). Second,
some adolescents are concerned about possible negative life events that may
happen to their parents and family members, such as health problems and divorce.
The third class of adolescents’ fears concern society-level events, such as nuclear war
(Solantaus, 1987) or environmental problems (Poole & Cooney, 1987). These differences
in adolescents’ fears and concerns reflect the historical time and topics that are
discussed in the mass media and in public during a particular era (Nurmi, 1991). For
example, the high rates of concerns related to nuclear war were typical in Western Europe
in the early 1980s, whereas concerns about global issues such as pollution have
been reported in subsequent decades (Nurmi, Salmela-Aro, & Ruotsalainen, 1994).
Personal Goals as Interpersonal Negotiation The construction of personal goals is not
solely the outcome of individual cognitive processing but is shared by other people, such
as parents, friends, and peers (Nurmi, 2001). For example, Meegan and Berg (2001)
found that college students appraised the majority of their goals as either directly or indirectly
shared, whereas only a minority of their goals were considered purely as their
own. When Malmberg (1996) asked adolescents about the key sources of information
concerning future education, occupation, and family life, parents were reported as the
most used sources followed by peers, school friends, the mass media, and schools.
The Role of the Family The kinds of goals adolescents have for their own future and
the kinds of goals parents overall have for their adolescent child’s future are closely similar:
Both adolescents’ and parents’ goals concerning adolescents’ future lives typically
concern education, occupation, family, and leisure activities, whereas the fears of both
groups concern health-related issues, education, and work (Lanz, Rosnati, Marta, &
Scabini, 2001). Similarly, parents and their adolescent child share similar kinds of educational
goals (Trusty & Pirtle, 1998), educational aspirations (Bandura, Barbaranelli,
Caprara, & Pastorelli, 2001), occupational aspirations (Jodl, Michael, Malanchuk, Eccles,
& Sameroff, 2001), and values overall (Kasser, Ryan, Zax, & Sameroff, 1995). In
100 Socialization and Self-Development
addition, mothers and fathers play a similar role in adolescents’ future-oriented goals
(Trusty & Pirtle, 1998).
Research has also shown that parental characteristics, beliefs, and parenting practices
are associated with the kinds of goals adolescents have. High level of education
among parents, involvement in adolescents’ school programs (Wilson & Wilson, 1992),
high levels of parental advice (Jenkins Tucker et al., 2001), close identification with the
parent (Jodl et al., 2001), low levels of parental control and positive family interaction
(Glasgow et al., 1997), and nurturance (Kasser et al., 1995) are associated in adolescence
with high educational aspirations, interest in future education and occupation,
and internality and optimism concerning the future.
Unfortunately, the vast majority of this research is based on cross-sectional data.
Consequently, we cannot be sure that it is parents who contribute to the kinds of goals
their adolescent children have. Although parents’ goals and values may provide a basis
for those of adolescents by means of modeling, advice, and negotiating (Nurmi, 2001),
there are several alternative explanations. First, both parents’ and adolescents’ goals
may be influenced by the same sources, such as socioeconomic background and related
cultural values. Second, it is possible that adolescents’ aspirations, such as emphasizing
the importance of education and subsequent high achievement, are reflected also in
parents’ aspirations concerning their children. Third, it is possible that the kinds of aspiration
and goals adolescents have concerning education, for instance, influence their
parents’ child-rearing patterns. In addition, siblings also play a role in the ways in which
adolescents think about their future (Jenkins Tucker, Barber, & Eccles, 1996).

SOCIALIZATION AND SELF DEVELOPMENT

INTRODUCTION
Adolescence is a crossroads from childhood to adulthood. Childhood experiences and
biological characteristics are transformed into interests, competencies, and self-beliefs
and begin to play an increasingly important role as the adolescent starts to make his or
her way toward adult life. This development is channeled by a variety of opportunities
and constraints in the adolescent’s social and institutional environments: Not all is possible,
but many things are. Out of these alternative pathways the adolescent has to select
the ones that appeal to him or her, or, in some cases, to significant others. Not
everything is attained, and surprises are part of the game. Therefore, ways to deal with
problems and unexpected events are developed. Along with these efforts and adventures,
adolescents begin to know themselves and to make reflections about who they
are. Young people are not alone in their efforts. Most of them live with their parents but
spend increasing amounts of time with their peers and friends. In these relations, advice
is given, interests raised, goals negotiated, solutions compared, and outcomes evaluated.
The aim of this chapter is to review what is currently known about the ways in
which adolescents make their ways into adulthood.
Adolescents face two broad challenges during the transition from childhood to adult
life: the entrance into production and reproduction fields of the culture and society. Entrance
into production includes becoming an economically independent individual who
is able to make his or her living in the society and economic system. This developmental
trajectory consists typically of a complex set of decisions concerning schooling, education,
and career. In turn, entrance into the reproduction domain includes a pattern of sequential
commitments to romantic relationships, building up intimate relations, founding
a family, and taking care of children. Although there is a lot of variation in how these
two broad challenges are approached, dealt with, and solved, these seem to be the key
challenges in all cultures and societies. The reasons for this are simple. When adolescents
85
The author would like to thank Kaisa Aunola, Terry Honess, and Katariina Salmela-Aro for their valuable
comments on the earlier versions of the manuscript and Rakel Nurmi, Maura Nurmi, and Katriina Aho-
Nurmi for secretarial assistance.
participate in these two processes, they become the agents in the reproduction of the society,
its economy, and its way of life (Nurmi, 1993). Moreover, working through these
two general challenges builds up a basis for the adolescent’s individuation from his or
her childhood family, as well as for his or her entrance into adult life and identity.
An increasing amount of research has been carried out on adolescence during the
past two decades. The majority of the studies has focused on examining adolescents’
behavioral characteristics, parental behaviors, or some other seemingly objective features
of adolescence. This research has provided important information about how
adolescents behave in many environments and about how this behavior changes with
age. Much less research has been carried out on how the adolescent’s mind works and
the kinds of consequences this adolescent psychology has for young people’s further
development. There are, however, a few relevant topics examined in the field of adolescent
research, such as self-concept, aspirations, coping, and identity. Some more recent
topics that are becoming popular in personality and social psychology are personal
goals, social strategies, problem solving, causal attributions, and identity narratives.
These topics have also begun to gain increasing attention in adolescent research.
In this chapter I review research on how adolescents’ minds work as they move to
adulthood, that is, what they think and feel about their lives as adolescents, what kinds
of interests they have, the kinds of tools they develop to deal with the challenges of adolescence,
and the ways in which they make stories about themselves later on. When reviewing
this research I used a few principles to make scientific generalizations of the
empirical research. The first principle is that before we make any generalization about
the findings, they should be replicated. Second, the source of the information on which
the results are based is considered. In some cases, such as parenting, information from
both parents and adolescents is a valid source of information. However, when the interest
is in a particular person’s thinking, such as the mother’s educational goals for
their child, the ways in which the adolescent perceives his or her mother’s goals is a secondary
type of information. Finally, the direction of influence is the key issue in developmental
psychology. However, it is difficult to deal with because experimental research
and intervention studies are rare. The major way to get evidence for the causality
in developmental processes is to use cross-lagged longitudinal data, which makes it possible
to control the previous level of the dependent variable before examining the later
impacts of the independent variables on the dependent variable.
A typical approach in review chapters such as this is to focus on one particular welldefined
research area and to exclude other topics. This approach may be problematic
for two reasons. The first is that researchers typically develop different kinds of conceptualizations
to deal with more or less the same phenomenon. Focusing on one conceptualization
only would mean, in fact, that not all important findings for a particular
phenomenon will be reviewed. Consequently, the aim of this chapter is to search for
the similarities across a variety of conceptualizations rather than to concentrate on analyzing
differences. Second, when focusing on one relatively narrow phenomenon and
a related research paradigm, there is a danger of losing sight of adolescent development
as a whole. In this chapter I make an effort to integrate research on adolescence under
a few umbrella concepts in order to provide a more holistic view of the young person.
In order to attain this goal, I first present a view in which adolescents’ socialization
is described in terms of four mechanisms: channeling, selection, adjustment, and re-
86 Socialization and Self-Development
flection. Then, research on a variety of more traditional concepts, such as futureorientation,
occupational aspirations, identity exploration, coping, causal attribution,
self-concept, and identity formation, are reviewed under these four headings. A few
topics, however, are excluded, such as academic motivation and achievement goals because
other chapters in this Handbook focus on them. The role of family and peers as
the interpersonal context for adolescent development is also considered. Finally, a few
future research directions and methodological issues are discussed.
CHANNELING, SELECTION, ADJUSTMENT, AND REFLECTION
During the adolescent years, an individual moves from being a member of the parents’
family to a full member of society. This development is characterized by four key mechanisms
(Figure 4.1): First, adolescents grow up in changing environments that channel
their developmental trajectories. A variety of sociocultural factors like cultural beliefs,
institutional structures, and historical events form such environments, which also
change rapidly from one age period to another (Nurmi, 1991). Such sociocultural and
institutional structures define an opportunity space for the adolescent that channels his
or her future-oriented motivation, thinking, and behavior. Second, as suggested by life
span theorists (Brandstädter, 1984; Lerner, 1983), adolescents are not passive targets of
environmental influences; rather, they select their developmental environments and future
life paths. Many psychological mechanisms are responsible for this selection: Motives,
interests, and personal goals direct adolescents’ exploration, planning, decision
making, and commitments and lead them to specific educational tracks, peers groups,
and leisure activities. Third, as a consequence of their efforts to select the direction of
their lives, adolescents end up having specific outcomes and receive feedback about
their successes and failures. Feedback about developmental outcomes, particularly
about failures and negative events, requires that young people adjust their goals, plans,
and thinking in order to cope successfully with the future challenges of their developmental
trajectories. Many psychological mechanisms, such as reconstruction of goals,
coping, and causal attributions, are responsible for this adjustment. Finally, after receiving
information about the outcomes of their efforts and ending up in a particular
life situation and social position, adolescents typically reflect about a variety of issues
concerning themselves and their lives: They construct conceptualizations about themselves
and tell stories to their parents and peers aimed at building up a coherent personal
identity

COGNITIVE AND BRAIN DEVELOPMENT

THE ADOLESCENT MIND: BUILDING AN INTEGRATED MODEL
The 1958 publication in North America of Inhelder and Piaget’s classic work, The
Growth of Logical Thinking from Childhood to Adolescence (following its 1955 publication
in France as “De la logique de l’enfant à la logique de l’adolescent: Essai sur la
construction des structures opératoires formelles”) is widely recognized as having
launched the systematic study of adolescent cognitive development. The introduction
to an English-language audience of a comprehensive model for understanding the cognitive
transition from childhood to adolescence inspired a generation of researchers to
undertake intensive investigations. The echoes reverberate still, even though direct assessment
of Piaget’s theoretical claims regarding formal operations has become less frequent
(Bond, 1998; Keating, 1990a; Moshman, 1998).
Some appreciation of the impact can be gleaned from a simple count of publications
on the topic before and after this watershed event. Using a comprehensive search engine
(PsychInfo, Cambridge Scientific Abstracts) and crossing the terms adolescent or
adolescence with cognition, cognitive development, or thinking, fewer than a dozen empirical
articles from 1872 (the earliest date for indexing) to 1960 were identified. In succeeding
decades, an exponential growth pattern in such publications is apparent, from
the low hundreds in the 1960s up to the low thousands in the 1990s. In contrast, this
new emphasis virtually displaced publications on psychometric research specific to
adolescence, a trend astutely noted at its cusp by Ausubel and Ausubel (1966). Crossing
adolescent or adolescence with intelligence or mental ability yielded over 1,000 titles
in the earliest period, but fewer than 100 in the 1990s.
The shift from a psychometric focus on intelligence and mental ability toward underlying
cognitive structure and process reflected larger trends in psychology generally and
cognitive science in particular from the early 1960s onward. In addition to the primary
goal of rescuing cognitive activity as a legitimate area of inquiry from the behaviorist
hegemony of the earlier period, a major scientific goal of the cognitive revolution
(Gardner, 1985; Johnson & Erneling, 1997; Pribram, 1986) has been to understand the
underpinnings of complex cognitive performance in the most elementary terms possible.
The study of cognitive development in adolescence fit comfortably within this larger
trend. The search for the essential elements of cognitive activity in adolescents yielded
several prime candidates, each of which spawned a substantial line of research. There
45
were several commonalities among these models. Each sought to identify the driver of
adolescent cognitive activity, producing what can be viewed as single-device accounts
(Keating, 2001a). In so doing, each also sought to answer the perennial question, “What
develops?” (Siegler, 1978). Each also sought to demonstrate that there were specifically
adolescent features of cognitive development.
Three major theoretical approaches to the core of adolescent cognitive development
during this initial efflorescence can be identified: cognition as reasoning, cognition as
processing, and cognition as expertise. These major accounts were not unrelated and
indeed arose sequentially in response to each other (Keating, 1980, 1990a). In computational
terms, one can view these as focusing, respectively, on developments in the design
of the operating system, on additions to the speed and/or capacity of the system,
or on changes in the size or structure of the database that the system has available.
A major theme of this review is that claims for independent developments in these
various aspects of adolescent cognition have not been supported by the weight of evidence,
even though important developments are clearly evident in each aspect of the
overall cognitive system. For example, Demetriou, Christou, Spanoudis, and Platsidou
(2002), using individual growth curve modeling from late childhood to adolescence,
found that more advanced levels of reasoning arise in part from bottom-up changes in
processing efficiency and working memory, but they also found that these lower order
elements are reciprocally affected from the top down. This interdependence has complicated
the search for the core of what develops—that is, identifying the fundamental
driver of adolescent cognitive development independent of other potentially confounding
cognitive shifts.
A Central Paradox
The inability to identify a single dominant source that explains what develops in adolescent
cognition has contributed to a central paradox. Despite the absolute growth in
the number of studies dealing with adolescent cognitive development just noted, and
despite the centrality of the questions that animated the major approaches, there is a
paradoxical (but widespread) view that there has been relatively little progress on these
central themes: “The study of cognitive development in adolescence has been moribund
for some time now, replaced by studies of adolescent decision making and judgment”
(Steinberg & Morris, 2001, p. 101). Compounding the paradox is an equally
widespread view that there are fundamental shifts in adolescent cognition and that
these changes are readily observable in important, broadly defined aspects of adolescent
thinking (Keating, 1990a; Moshman, 1998). The power of this paradox is further
reinforced by the emerging understanding of the dramatic nature and long reach of
pubertal events (Angold, Costello, Erkanli, & Worthman, 1999; Angold, Costello, &
Worthman, 1998; Susman & Rogol, this volume), which sustains the belief that there
should be large and readily identifiable shifts in both cognitive and brain development.
Can this paradox be resolved? To begin to answer this difficult challenge, we need to
attend to the subsequent trajectories of research that originated in the different theoretical
perspectives noted earlier (Keating, 2001a). This is of more than historical interest.
As these approaches have pursued their largely separate paths, they have en-
46 Cognitive and Brain Development
countered highly similar dilemmas. Indeed, they are similar not only by analogy, but
also as homology. Each has confronted, I argue, the core problem of all single-device
accounts. The greater the refinement of parameters to measure the theoretically targeted
developmental mechanism, the less these parameters are able to account for
broad changes that the theories were designed to explain (Keating, 1996b; Keating,
List, & Merriman, 1985).
In short, researchers have long sought to explain the readily apparent and broad
changes in adolescent thinking by identifying the underlying mechanism of “what develops”
(Siegler, 1978). In pursuing this agenda, it is logical to identify and measure parameters
of the targeted mechanism as precisely as possible: pure logic, pure processing
efficiency, pure capacity, and so on. As the evidence reviewed in this chapter demonstrates,
this research agenda has yielded much new knowledge about adolescent cognition
but has encountered significant problems in answering the original question.
To the extent that the strategy has succeeded in purifying the parameters of specific
underlying mechanisms, it has been at the cost of explaining variance in the broader
cognitive shifts. Moreover, in studies where multiple mechanisms have been examined,
especially in longitudinal designs (e.g., Demetriou et al., 2002), there is strong evidence
for interdependence among them. It seems increasingly unlikely that any single-device
explanation of the major shifts in adolescent cognition will suffice. Confronting these
recurring limitations, lines of research have bifurcated and branched, yielding a burgeoning
complexity of questions and paradigms that focus on adolescent cognition.
As Steinberg and Morris (2001) accurately noted, this has redirected much of the research
attention away from the original questions about the core of adolescent cognitive
development toward a search for answers to specific practical questions. These have
been more typically addressed by an applied cognitive science with a more contextspecific
focus on pathways to expertise, on the role of teaching and learning in the acquisition
of expertise, and on the development of judgment and decision making (e.g.,
Keating, 1990b; Klaczynski, Byrnes, & Jacobs, 2001; Kokis, Macpherson, Toplak, West,
& Stanovich, 2002; Kuhn, Garcia-Mila, Zohar, & Andersen, 1995; Kuhn & Pearsall,
2000; Kwon & Lawson, 2000; Kwon, Lawson, Chung, & Kim, 2000; Lawson et al., 2000).
In pursuing these more applied questions, the dilemmas of interdependence and insufficiency
of single-device accounts reemerge for the same reasons and in the same way.
More provocatively, this paradox—of major shifts that are not explained by any
single developmental mechanism—can be viewed as a strong indication that a more integrative
theoretical account is needed. If one adopts this position, as this review does,
we then need to ask what shape such an integrative account might take, what evidence
may be available to support such an account, and what would constitute an effective research
agenda to probe an integrated model. The prospects for an integrative account
have been substantially enhanced by recent major advances in the neurosciences (e.g.,
Casey, Giedd, & Thomas, 2000; Giedd et al., 1999; Johnson, 2001; Luna et al., 2001;
Nelson, 1999; Paus et al., 1999; Sowell, Delis, Stiles, & Jernigan, 2001; Sowell, Trauner,
Gamst, & Jernigan, 2002; Steingard et al., 2002), in comparative neuroanatomy across
closely related primate species that illuminate core issues of human cognitive evolution
(Donald, 2001; Rilling & Insel, 1999), in the increasing sophistication of analyses of longitudinal
data and individual growth curves (Demetriou et al., 2002; McArdle, Ferrer-
The Adolescent Mind: Building an Integrated Model 47
Caja, Hamagami, & Woodcock, 2002), and in a deepened understanding of the critical
role of culture and context in the shaping of cognitive and brain development (Donald,
2001; Francis, Diorio, Plotsky, & Meaney, 2002).
An Emergent Resolution
Drawing on these various sources, the nature of an integrated account has begun to
emerge. It is sketched in this introductory section and elaborated in subsequent sections.
What lies at the core of adolescent cognitive development is not likely to be any
single device that drives it. Rather, it is the attainment of a more fully conscious, selfdirected,
and self-regulating mind that characterizes the adolescent transition. This is
achieved principally through the assembly of an advanced executive suite of capabilities
(Donald, 2001), rather than through specific advancement in any one of the constituent
elements. This represents a major shift in prevailing views of cognition, going
beyond the search for underlying elements (or hidden “demons”; Dennett, 1991) that
are formed and operate largely outside awareness. Such coordination of cognitive elements
resonates with contemporary work on metacognitive and metastrategic development.
In describing the core difference between young and mature scientists, for
example, Kuhn and Pearsall (2000) noted that both seek to coordinate theory and evidence,
but that in the latter, “the coordination of theory and evidence is carried out under
a high degree of conscious control” (p. 115).
Recent advances in developmental neuroscience, propelled by dramatic advances in
imaging technologies, point toward a similar resolution. A broad outline of the most
significant and cognitively relevant developments in the adolescent brain has begun to
coalesce very recently (Casey et al., 2000; Johnson, 2001). Much of the underlying action
is focused on specific developments in the prefrontal cortex, but with an equally
significant role for rapidly expanding linkages to the whole brain (Donald, 2001; Luna
et al., 2001; Newman & Grace, 1999). This complex process of assembly is supported
by increasingly rapid connectivity (through continued myelination of nerve fibers), particularly
in communication among different brain regions, and by significant and localized
synaptic pruning, especially in frontal areas that are crucial to executive functioning
(Giedd et al., 1999; Sowell et al., 2001, 2002; Steingard et al., 2002).
It is noteworthy that the most marked differences between adult humans and nonhuman
primates (Rilling & Insell, 1999) occur precisely in those features of brain development
that emerge most strikingly during adolescence: differentially greater increases
in neocortical volume (beyond the expected increase owing to larger brain volume overall);
differentially greater gyrification of the prefrontal cortex, indicating a more convoluted
design that affords both more capacity for central coordination and more rapid
communication; and a greater relative increase in cerebral white matter relative to neocortical
gray matter, “suggesting that axonal connections between neocortical neurons
may increase faster than the number of neurons as brain size increases” (p. 222). The
prefrontal cortex is thus among the latest brain systems to develop, both phylogenetically
and ontogenetically, especially the dorsolateral prefrontal cortex (Fuster, 2000).
Its importance for adolescent cognitive development can be inferred from this convergence
but is more directly evident from its integrative functions.
The prefrontal lobes have long been seen as central to the coordination of cognitive
48 Cognitive and Brain Development
activity (Case, 1992; Stuss, 1992), whose function is to sustain “many high-level metacognitive
operations, such as self-evaluation, long-term planning, prioritizing values,
maintaining fluency, and the production of appropriate social behavior” (Donald,
2001, p. 198). The reach and complexity of the prefrontal cortex has been further emphasized
in recent work identifying important details of its structure and function (Barbas
& Hilgetag, 2002; Fuster, 2000; Fuster, Van Hoesen, Morecraft, & Semendeferi,
2000; Watanabe, 2002). In particular, the temporal integration of retrospective memory
and preparatory set in the dorsolateral prefrontal cortex (Fuster, 2000) creates the
conditions for a broader, more fully conscious control of cognition and behavior. In
other words, the narrow window of active awareness that is the focus of much of experimental
cognitive science, which seems to undermine assertions of a broader consciousness
with significant agency in decision making and planning, captures too little
of the important cognitive action (Donald, 2001). In addition, the close connection and
communication among regions of the prefrontal cortex that are more cognitive with
those that have important linkages with emotional processing, especially the orbitofrontal
cortex (Barbas & Hilgetag, 2002), support the view of the prefrontal cortex as a
more general synthesizer of experience and governor of action. Thus the role of the prefrontal
cortex as not only an integrator of cognitive functions, but also a governing regulator
of emotion, attention, and behavior, takes on special importance during adolescence
in three ways.
First, patterns of individual differences in how cognition, emotion, and behavior become
integrated during adolescence may well have a long reach with respect to the development
of psychopathology (Steinberg et al., in press) and to normative habits of
mind (Keating, 1996b, 1996c) that influence trajectories of competence and coping.
Second, the pubertal influences on many hormonal and neuroendocrine systems are
dramatic (Angold et al., 1998, 1999; Susman & Rogol, this volume), entailing the cascading
reorganization of body and brain systems. Third, recent evidence from animal
models demonstrated the partial reversibility of damage acquired during early development,
at both the behavioral and the physiological levels, as a function of enriched
environments during puberty (Francis et al., 2002). In combination, this evidence
points strongly toward both enduring (but not limitless) neural plasticity and the critical
role of developmental experience in shaping future developmental trajectories in
cognition and behavior (Nelson, 1999; Nelson, Bloom, Cameron, Amaral, Dahl, &
Pine, 2002).
Recent research directions thus point toward the distinct possibility that adolescence
may be a sensitive or critical developmental period, much like early development
in its ability to shape future trajectories and in the biological embedding of developmental
experiences as the principal method through which this occurs (Boyce & Keating,
in press; Keating & Hertzman, 1999; Meaney, 2001). The major changes during
adolescence just outlined form the essential substrate for adolescence to function as a
critical developmental period: the interdependence and developmental coordination of
numerous cognitive elements, and of cognition with emotion and behavior; the role of
puberty in a fundamental restructuring of many body systems; the apparent concentration
of changes in the adolescent brain in the prefrontal cortex (which serves as a
governor of cognition and action) together with the enhanced interregional communication
between the prefrontal cortex and other brain regions; and in the evidence for
The Adolescent Mind: Building an Integrated Model 49
substantial synaptic pruning and for nontrivial physiological reversibility of behavioral
and neuroendocrine patterns arising from early developmental experiences.
Brain, Culture, and the Centrality of Consciousness
The reemergence of consciousness and its development as a legitimate area of scientific
inquiry (Chalmers, 1996; Dennett, 1996; Donald, 2001; Ferrari, Pinard, & Runions,
2001; Searle, 1997) has increased the probability that adolescence may be a critical developmental
period for cognitive development and for the myriad ways that cognition
plays a role in emotion and action. The late development of the prefrontal cortex in phylogeny
and ontogeny, as well as its central integrative function, provides a crucial starting
point for understanding the distinctive features of human cognition generally and
adolescent cognition specifically.
As McGinn (1999) noted, “Consciousness is hard to miss but easy to avoid, theoretically
speaking” (p. 44). The classic subject-object and mind-body problems in
epistemology (and philosophy more generally) drove consciousness out of scientific
scrutiny in two directions, either by explaining it away through reductionist accounts
that allowed it to exist only as an epiphenomenon resting on the actions of more fundamental
cognitive automata (Dennett, 1991), or, alternately, by awarding it a privileged
position beyond objectifying scientific inquiry, to be understood by largely phenomenological
methods. But as McGinn (1999) observed, consciousness just won’t go
away, posing again the question: “How does consciousness fit into the scientific world
picture. . . ?” (p. 44).
Ferrari et al. (2001) argued that Piaget (for whom, they noted, the scientific study of
consciousness never became unrespectable) proposed a solution that should be revisited.
Specifically, the physiological “rules” that enable cognitive activity and the (psycho)
logical “rules” that govern conscious awareness coevolved in a “sophisticated form
of parallelism” (p. 195) that exhibits substantial isomorphism and leads toward an “integrative
monism” (p. 195) that may never actually arrive.
A Piagetian anecdote about his encounter with Soviet psychologists (in a new translation
by Ferrari et al., 2001, p. 199), while revealing heavy ideological baggage, emphasizes
the convoluted epistemological and philosophical argumentation that the scientific
study of consciousness confronts. In the anecdote, Piaget is cleared of the charge
of being an idealist on the grounds that he grants primacy to the preexistence of objects
before a knower, even though he maintains a strong stance that the origin of knowing
lies in the first actions upon objects. What the Soviets were probing is the essential (but
creative) tension at the heart of the Piagetian project (Keating, 1990d, pp. 312–315), between
the specification of closed structures with the definable end point of formal reasoning
(an idealist position despite the Soviet acquittal), and the identification of an
open-system, constructivist process that codevelops iteratively through action on the
world (sufficiently objectivist to satisfy his interlocutors on that occasion). As I have
previously argued (Keating, 1990d), it is the former position, the closed structure with
defined end points, that was initially more amenable to cognitive developmental investigation,
and hence defined the limits of much of the research on adolescent cognition.
The open systems view, more compatible with much intervening theoretical work, sup-
50 Cognitive and Brain Development
ports the identification of Piaget as a root theorist of the development of consciousness
(Ferrari et al., 2001).
Relying more heavily on recent evidence in human evolution and neuroscience, and
thus eschewing many of the ideological issues, Donald (2001) proposed a framework
that is compatible with these Piagetian arguments that are based in the method of genetic
epistemology. Donald’s (2001) core argument is that the evolution of the human
brain, especially as it branched from the broader primate lineage, was quintessentially
social: “The key to understanding the human intellect is not so much the design of the
individual brain as the synergy of many brains. We have evolved an adaptation for living
in culture, and our exceptional powers as a species derive from the curious fact that
we have broken out of one of the most critical limitations of traditional nervous systems—
their loneliness, or solipsism” (p. xiii).
It is important to distinguish this notion of the fundamentally social nature of human
mind from the line of research in organizational behavior launched by Janis’s
(1972) seminal work on groupthink. That theoretical construct has focused on the
mechanisms by which ineffective or poor decision making can occur in the context of
(usually small) group dynamics (Flippen, 1999; Jones & Roelofsma, 2000; Park, 2000;
Turner & Pratkanis, 1998), such as failure of monitoring, premature concurrence, failure
to consider unconventional options, or perceived risk of excluding oneself from the
group through disagreement (Baumeister & Leary, 1995). The fundamentally social nature
of cognition and consciousness may be a necessary condition for groupthink, but
the multifaceted nature of social or collective mind cannot be accurately characterized
as groupthink. It is interesting to note, however, that despite a substantial line of research
on how peers may influence individual decision making during adolescence
(Ormond, Luszcz, Mann, & Beswick, 1991; Payne, 2002; Steinberg & Silverberg, 1986),
there is little research on groupthink among adolescents. This is somewhat surprising
given the group context that often underlies immaturity of decisions (Cauffman &
Steinberg, 1995; Dishion, Eddy, Haas, Li, & Spracklen, 1997) and the salience of the
sense of belonging that is an important aspect of the adolescent self (Marshall, 2001).
There is a real tension between the formative role of society in essential cognitive development
and the need to develop an autonomously critical habit of mind (Keating,
1996c), and clearly this tension is a key dynamic in adolescent cognition.
Donald (2001) proposed three major transitions as levels of consciousness beyond
the episodic awareness that we share with our nonhuman primate cousins. Each rests
on continuing development and refinement of the “executive suite” that is concentrated
in the prefrontal cortex (including its interregional connectivity): “(1) more precise and
self-conscious control of action in mimesis; (2) richer and faster accumulation of cultural
knowledge, in speech; and (3) much more powerful and reflective cultures, driven
by symbolic technology” (p. 262). Note that each of these proceeds as a coevolution of
brain and culture; indeed, the signal species characteristic of Homo sapiens can be
thought of as cultural mind sharing that activates individual minds (whose brains have
been designed, as it were, by evolution to participate in just such activity). In this light,
there is an essential concordance on the centrality of interactive constructionism between
Vygotsky’s (1979) cognitive socialization and Piaget’s (1965) “internal interactionism”
(Ferrari et al., 2001, p. 198).
The Adolescent Mind: Building an Integrated Model 51
The implication of these convergences is that there exist potentially homologous
qualitative transitions in the evolution of the human brain, the nature of primate group
interaction (episodic, mimetic, mythic, and theoretic; Donald, 2001), and adolescent
cognitive and brain development. The essence of the homology lies in the nature of human
consciousness, including its phylogeny, ontogeny, and inseparability from culture
and context. Fully attained human consciousness is thus potentiated by key developments
in the brain that are late arrivals in evolutionary history and become fully available
for assembly in individual ontogeny only during the adolescent transition. But this
potential assembly becomes actual only in close interplay with the surrounding cultural
and cognitive web, in which the individual adolescent experiences culture not passively
as an external entity, but rather as an active force (Swidler, 1986) that can be used to
both define and achieve goals, and serves simultaneously as a fundamental coconstructor
of cognition and consciousness.
Understanding how adolescence may function as a critical developmental period
will be a major challenge. The necessity of incorporating the multiple interactions of
brain-biology, behavior-cognition, and culture-context implies a level of complexity
that is daunting. This poses two risks to a productive research agenda that can advance
our understanding. First, the complexity may be overwhelming, leading instead toward
continued fragmentation and inattention to core questions—the central paradox described
earlier. Second, the need for coherence may lead to an overly facile acceptance
that the mere proposal of a global homology centered on the emergence of consciousness
fully resolves the paradox. It does not, because consciousness emerges (phylogenetically,
historically, and ontogenetically) not as one thing, but as the assembly of
many things (Donald, 2001). Each of its many subsystems retains some degree of ongoing
modular independence in the context of increasing systemic interdependence.
Their coordination into a more centrally governed metasystem is unlikely to be smooth
developmentally or uniform in execution. Indeed, the individual and developmental
anomalies of assembly are readily apparent as performance or procedural intrusions
that muddy the waters of what might otherwise be observed as a clear progression to
fundamental logical competence (Overton, 1990).
To summarize, the initial stages of research on adolescent cognitive development focused
logically and necessarily on isolating key cognitive components. The recent emergence
(or reemergence) of consciousness as a legitimate and necessary focus of cognitive
research (Donald, 2001) has been driven by a need to understand how those components
get assembled into a complex, coordinated cognitive system. The accumulating
evidence is particularly relevant to adolescent cognitive development, reflecting the
broader movement in cognitive science as it comes to terms with cognitive, cognitiveaffective,
and developmental neuroscience. In this light, understanding adolescent cognitive
development will have to play a central role in understanding human consciousness
more generally, as research in a number of related fields points with increasing
specificity to this period of development as the one in which the processes of assembly
are at their peak.
Contemporary evidence also supports the view that adolescents are biologically susceptible
to the embedding of experience in brain and body systems. Thus, a comprehensive
research agenda will require a much more detailed understanding of the ways
in which context organizes the salient experiences of adolescents (see chapters in Part
52 Cognitive and Brain Development
II of this volume, especially that by Larson & Wilson). If the adolescent mind is coconstructed
by the potentiation of developing cognitive capacities through active engagement
with culturally embedded knowledge and meaning systems, then the specific
ways in which adolescents engage their cognitive universe become crucial. In contrast,
identifying the most salient aspects of early development in order to understand how
they may become biologically embedded in the infant and young child may be relatively
easier than in the adolescent, with the increased complexity of the relevant contexts and
the increased ability for individual choice in the selection of contexts.
The principal goal of this review is thus to examine closely (but not exhaustively,
given the breadth of the extant literatures) the major research efforts on adolescent cognitive
and brain development, to identify common themes and findings that cut across
the disparate research agendas, and to situate those themes with respect to an emergent
theoretical perspective that integrates them. To move this research agenda forward productively,
emerging methodologies that support interdisciplinary cross-fertilization
will be essential. Wilson (1998) argued for an innovative methodological approach that
seeks consilience of evidence among biological, social, and human sciences. Although
hard to achieve, the understanding of adolescent cognitive development requires such
an integration, and the evidence reviewed in this chapter suggests that the prospects are
promising.
Following this first section, in which the overall argument has been outlined, the balance
of the review is organized as follows. In the second part, a more detailed consideration
of the major lines of research on adolescent cognitive development is provided,
and their theoretical and empirical implications for an integrated model are identified.
In the third part, the prospects for grounding adolescent cognitive development in
underlying biological and brain development are discussed further, with a particular focus
on emerging evidence from the neurosciences that supports (or even requires) an integrated
model. In the fourth and final part, the role of context in adolescent cognitive
development is addressed in light of these newly emerging perspectives. In contrast to
conventional approaches that sought to partial out or control for context in order to
identify purely cognitive parameters, arguments for the role of enculturation as an active,
integral, and endogenous feature of adolescent thinking are reviewed (Donald,
2001; Keating, 1996b, 1996c; Keating & Sasse, 1996).

PUBERTY AND BEHAVIOR, EMOTIONS, AND COGNITION

Until the last two decades, studies of pubertal processes considered primarily physical
morphological characteristics or menarche in assessing the relationship between biological
changes and psychological development. These studies now are enriched by assessment
of biological substances—specifically, hormones—that are essential for pubertal
development.
Pubertal Status and Pubertal Timing
The literature linking puberty and psychological development includes assessment that
considers both pubertal status and timing of puberty. Pubertal status refers to the degree
of physical maturation on indicators that include breast, genital, and pubic hair
Puberty and Behavior, Emotions, and Cognition 23
development and hormone levels. Timing of puberty refers to pubertal status relative to
same-age peers.
Pubertal Status: Hormones
The use of hormones to assess degree of pubertal development is a relatively new undertaking.
In the following section, hormone levels are examined in relation to their
contribution to behavior, emotions and cognition.
Testosterone and Estrogen: Antisocial Behavior “A focus on either social or biological
factors can yield only part of the story of aggressive and violent behaviors: integrative
investigations are essential to complete the picture” (Cairns & Stoff, 1996, p. 338). Relative
to other domains, the integration of biological and psychological processes in
relation to antisocial behavior has been evident for some time. Increases in antisocial
behavior (physical aggression, relational aggression, conduct disorder symptoms, behavior
problems, delinquent and violent behavior, and early and risky sexual activity
and arrests) have been attributed to changes in hormones, physical maturation, altered
reactivity to life stressors, and, most recently, brain changes during puberty. An unresolved
issue is whether antisocial behavior existed prior to puberty but became transformed
to more annoying or more serious problems at puberty or whether problems
emerge de novo at puberty.
The links between the biology of puberty and problem behavior have been extensively
reviewed elsewhere (Brain & Susman, 1997; Buchanan, Eccles, & Becker, 1992).
Major advances in relating pubertal status and psychological parameters partially result
from advances in hormone assay technologies, whereby hormones can reliably and
sensitively be measured in small quantities of blood and saliva.
The steroid hormone testosterone (T) is implicated in physical aggression in animals
and antisocial behavior in humans (Brain & Susman, 1997; Mazur & Booth, 1998). The
relationship between T and problem behavior is hypothesized to derive from pre- and
early postnatal organizational effects of hormones on brain development and later activational
influences when T begins to rise at puberty. The argument is that because
males are exposed to higher concentrations of androgens than females during pre- and
postnatal development and onward, and because males tend to express more physical
aggression than females, androgens must be implicated in aggressive behavior and
dominance in males (Mazur & Booth, 1998). Because T rises at puberty and externalizing
behavior problems also rise at puberty, it follows that T is hypothesized to influence
antisocial behavior.
Evidence for the relationship between T and aggressive behavior is derived from a
few correlational and experimental studies. In boys in the later stages of pubertal development,
Olweus, Mattson, Schalling, and Low (1988) examined the causal pathway
between T and provoked and unprovoked aggression and reported that T exerted a direct
causal path on provoked aggressive behavior. T appeared to lower the boys’ frustration
tolerance. For unprovoked aggressive behavior (starting fights and verbal aggression),
the findings were somewhat different. T had no direct effects on unprovoked
aggressive behavior, but there was an indirect effect of T with low frustration tolerance
as a mediator of aggressive behavior. The authors concluded that higher levels of T
24 Puberty and Psychological Development
made the boys more impatient and irritable, in turn increasing readiness to engage in
unprovoked aggressive behavior.
Higher levels of T appear to affect observable behavior in subtle ways. Adolescent
boys’ perceptions of dominance were reflected in peers’ T concentrations (Schaal,
Tremblay, Soussignan, & Susman, 1996). T was significantly higher in peer-perceived
leaders than in nonleaders. In addition, T levels and body mass additively predicted social
dominance (Tremblay et al., 1998). It is not yet evident whether social dominance
leads to higher T levels or whether higher T and greater body mass lead to higher social
dominance.
The relationship between T and antisocial behavior is far from consistent across
studies. T was positively related to substance use (Bauman, Foshee, Koch, Haley, &
Downton, 1989; Martin et al., 2001), coitus in females (Halpern, Udry, & Suchindran,
1997), and sexual activity in males (Halpern, Udry, & Suchindran, 1998), but there was
a negative relationship between T and behavior problems in healthy young boys (Susman
et al., 1987). Similarly, there was no relationship between a diagnosis of conduct
disorder problems and T in 4- to 10-year-old children (Constantino et al., 1993). In
girls, T was not related to aggressive or dominance behaviors in three studies that included
early-puberty girls (Brooks-Gunn & Warren, 1989; Inoff-Germain et al., 1988;
Susman et al., 1987). It is noteworthy that the associations between antisocial behavior
and T are less apparent in girls and in male children and younger adolescents (Brooks-
Gunn & Warren, 1989; Constantino et al., 1993; Nottelmann et al., 1987; Susman et al.,
1987) than in older adolescents (Olweus et al., 1988) and adults (Mazur & Booth, 1998).
These developmental inconsistencies should be expected given the different constructs
assessed across studies. Questionnaires that assess the molar aspects of aggressive behavior
may not have adequate sensitivity for capturing subtle differences in the behavior
of adolescents that covary with T levels. The relatively inconsistent links between T
and antisocial behavior in adolescents compared to adults indicates that elevated T and
antisocial behavior may be a consequence of aggressive behavior (Constantino et al.,
1993). However, a causal influence for T in behavior should be considered. Boys who
consistently displayed disruptive behavior problems and were anxious across six years
were significantly lower on T than were boys who were not disruptive and anxious
(Schaal et al., 1996). These disruptive and anxious boys were also later in their pubertal
development. The effect of antisocial behavior on suppression of gonadal steroids
may be mediated by stressors and related hormones.
Experimental studies are the preferred approach for establishing the cause-effect relationship
between hormones and antisocial behavior. To examine this cause-effect relationship,
T or estrogen was administered to delayed-puberty boys and girls in a
placebo-controlled, randomized, double-blind, crossover design study. The boys and
girls were being treated with physiological doses of T (boys) or conjugated estrogens
(girls) (Finkelstein et al., 1997; Liben et al., 2002; Schwab et al., 2001; Susman et al.,
1998). Each 3-month treatment period was preceded and followed by a 3-month placebo
period. The doses of gonadal steroids were calculated to simulate concentrations in
blood in normal early (low dose), middle (middle dose), and late (high dose) pubertal
adolescents. Significant increases in aggressive impulses and physical aggression against
peers and adults were seen in boys but only at the middle dose. In contrast, significant
Puberty and Behavior, Emotions, and Cognition 25
increases in self-reported aggressive impulses and in physical aggression against both
peers and adults were seen in girls at the low and middle dose but not at the high dose of
estrogen (Finkelstein et al., 1997). In brief, experimental treatment with T and estradiol
resulted in changes in aggressive behavior, suggesting a causal role for these hormones.
The effects of estrogen are less frequently examined in relation to antisocial behavior
than are those of T. In the few studies that have examined estrogen, the relationship
between T and aggressive behavior in girls mimics the relationship between T and aggressive
behavior in boys (Inoff-Germain et al., 1988). The lack of progression of research
on estrogen and antisocial behavior reflects two issues. First, only males were included
in the majority of studies on hormones and antisocial behavior, as physically
aggressive behavior and violence occur more frequently in men and aggressive and violent
behavior in girls rarely comes to the attention of the judicial system. Second, the
logic of the arguments regarding T, aggressive behavior, and brain development does
not take into account the empirical findings on the different forms of aggressive behavior
in males and females. Females tend to show higher levels of relational aggression
than do boys. Therefore, the relationship between female phenotypic aggressive
behavior and hormones requires reconsideration. In human adolescents, dominance
may be a productive area to consider for establishing the dynamic integration between
hormones and social hierarchies as these hierarchies are established and dissolve rapidly
in adolescent peer groups.
Emotions The role of pubertal status in emotions is of sustained interest given that
depression symptoms begin to rise during the middle to late pubertal years (Lewinsohn,
Clarke, Seeley, & Rohde, 1994; Nolen-Hoeksema & Girgus, 1994). The stressful
change hypothesis suggests that girls experiencing the pubertal transition will manifest
higher levels of distress than will pre- or postpubertal girls (Ge, Conger, & Elder,
2001b). This hypothesis is based on the assumption that puberty is a stressful transition
that requires reorganization of adaptive coping strategies (Caspi & Moffitt, 1991).
Some researchers have argued that it is the novelty of a situation, rather than the magnitude
of the stressor, that leads to emotional distress in adolescents (Susman, Dorn,
Inoff-Germain, Nottelmann, & Chrousos, 1997). This perspective leads to the prediction
that given the novel nature of the hormonal and physical growth changes, puberty
constitutes a stressful adolescent transition.
In those studies that examine hormones and emotion, there are group differences for
depression in girls at different stages of puberty but a larger effect for T than for stage
of pubertal development (Angold, Costello, Erkanli, & Worthman, 1999). When Tanner
stage and hormones were entered simultaneously into a statistical model, the effect
for Tanner stage became nonsignificant, but the effect for T and estradiol remained unchanged.
In a parallel study, girls were grouped by pubertal breast stages and four stages
of estradiol secretion (Warren & Brooks-Gunn, 1989). The hormonal stages revealed a
significant curvilinear trend for depressive affect (increase, then decrease), impulse control
(decrease, then increase), and psychopathology (increase, then decrease), indicating
significant differences in these indexes during times of rapid increases in hormone
levels. In the clinical trial study just described, adolescents with delayed puberty treated
with physiological doses of T or estrogen showed few changes in emotions as a result
of treatment, with the exception of increased withdrawn behavior in girls (Susman et al.,
26 Puberty and Psychological Development
1998). Collectively, the studies with adolescents who are progressing normally through
puberty demonstrate an association between pubertal status and depression.
Adrenal Androgens and Cognition The role of hormones in cognition has not received
much attention in the last decade. In a recent study, maturational status as indexed by
T was related to better spatial abilities (Davison & Susman, 2001). As T increased, there
was a corresponding increase in spatial ability in boys, and to a lesser extent in girls. In
an experimental sex hormone treatment study, spatial performance showed traditional
sex differences but did not vary with levels of actively circulating sex steroids (Liben et
al., 2002). Further longitudinal research is required to resolve the question of how pubertal
hormones and cognition change in an integrated fashion.
Adrenal Androgens
Adrenal androgens represent a class of hormones that traditionally received little attention
in relation to behavior. The adrenal androgens DHEA, DHEAS, and Δ4-A are
secreted by the adrenal glands and begin to rise during adrenarche.
Adrenal Androgens and Problem Behavior In the last two decades reports began to appear
showing relationships between adrenal androgens and antisocial behavior in adolescents.
In healthy pubertal-age girls, DHEAS correlated negatively with aggressive
affect (Brooks-Gunn & Warren, 1989), and the interaction between negative life events
and DHEAS and aggressive affect also was significant. Girls with lower concentrations
of DHEAS who experienced negative life events had more aggressive affect than did
girls with fewer negative life events. In a study that included healthy 9- to 14-year-old
boys and girls, there was a relatively consistent pattern of higher DHEA and Δ4-A and
lower DHEAS and problem behaviors (Nottelmann et al., 1987; Nottelmann, Inoff-
Germain, Susman, & Chrousos, 1990; Susman, Dorn, & Chrousos, 1991; Susman et al.,
1987). Adrenal androgens also were correlated with dominance in girls while interacting
with their parents (Inoff-Germain et al., 1988). The links between adrenal androgens
and problem behavior extended to sexual behavior as well. Higher levels of adrenal
androgens were related to sexual behavior and activities during adolescence (Udry
et al., 1985; Udry & Talbert, 1988). In addition, youth with conduct disorder (CD) had
significantly higher levels of DHEA and DHEAS than did non-CD youth and reported
higher intensity of aggression and delinquency (van Goozen, Matthys, Cohen-Kettenis,
Thijssen, & van Engeland, 1998). Support for the links between adrenal androgens and
behavior problems was reported in girls with early adrenarche. These girls had higher
levels of adrenal androgens and more behavior problems than did the on-time girls
(Dorn, Susman, Nottelmann, Inoff-Germain, & Chrousos, 1999). Higher levels of adrenal
androgens may be an etiological process in the higher incidence of behavior problems
in premature-adrenarche girls.
Adrenal Androgens and Emotions There is a relatively consistent pattern of high adrenal
androgens associated with negative affect (Nottelmann et al., 1990; Nottelmann et
al., 1987; Susman et al., 1991; Susman et al., 1987). DHEAS levels interact with timing
of puberty and depression in girls. Girls with high levels of DHEAS and early maturation
had the highest emotional arousal and depressive affect scores (Graber, Brooks-
Puberty and Behavior, Emotions, and Cognition 27
Gunn, & Warren, in press). Girls with premature adrenarche, who also have higher
levels of adrenal androgens, were more anxious than were their peers with on-time
adrenarche (Dorn et al., 1999). In addition, higher levels of DHEA predicted the onset
of the first episode of major depression during adolescence (Goodyer, Herbert, Tamplin,
& Altham, 2000). As is the case for sex steroids, the described associations do not
imply causality. Variations in levels of hormones may arise from more distal genetic or
experiential origins than recent life events and behavior.
Pubertal Status: Physical Maturation
The relationship between pubertal status (i.e., degree of physical development) and
psychological development is hypothesized to result from changing social roles, including
increasing family and peer pressures, and cultural expectations for mature behavior.
The assumption is that problem behavior and negative emotions will increase
with advancing physical development independent of age.
Antisocial Behavior Indeed, more advanced pubertal status contributed significantly to
predicting female delinquency (Flannery, Rowe, & Gulley, 1993), symptoms of attentiondeficit/
hyperactive disorder (ADHD), oppositional disorder (ODD), and conduct disorder
(CD; Ge, Brody, Conger, Simons, & Murry, 2002). More advanced pubertal development
provides adolescents with opportunities to become involved with older and
deviant peers.
Emotions Tanner stage had a larger effect on depression than did age, suggesting that
biological change rather than a specific age is related to depression in both boys and
girls (Angold, Costello, & Worthman, 1998; Ge et al., 2001b; Ge et al., 2002). Additionally,
the association between pubertal status and internalizing distress is stable over
time. Pubertal status in 7th grade was significantly related to both internalized distress
and hostility assessed at Grades 8 and 10, respectively, and to externalized hostility at
Grade 9 (Ge, Conger, & Elder, 2001a). Overall, more advanced stages of physical development
favored more negative emotions.
Family The classic study by Steinberg and Hill (1978) showed that family-adolescent
interactions are moderated by pubertal development. Conflict between mothers and
sons was highest during midpuberty. The same findings emerged in African American
adolescents whose parents reported having more verbal aggression with sons during
midpuberty than during early or late puberty (Sagrestano, McCormick, Paikoff, &
Holmbeck, 1999). The sons reported more “hot” issues and having hot discussions
when they were more physically developed. However, the importance of midpubertal
status in family conflict is not consistent across studies. Later as opposed to midpubertal
status also was associated with more conflict and diminished closeness with parents
(Crockett & Petersen, 1987; Savin-Williams & Small, 1986). The lack of consensus regarding
pubertal status, conflict, and family interactions is not surprising given the
variation in methods for assessing family interaction.
Cognition Cognitive maturation normatively advances with chronological age rather
than pubertal maturation. For instance, spatial ability was associated with chronolog-
28 Puberty and Psychological Development
ical age but not with pubertal stage in a sample of healthy young adolescents (Davison
& Susman, 2001). As discussed earlier, pubertal status in delayed-puberty adolescents
was not associated with spatial ability (Liben et al., 2002) and thus denotes consistency
across studies.
Psychopathology Pubertal status was associated with a sharp increase in rates of
unipolar depression (Angold & Worthman, 1993). Girls begin to have higher rates of
both diagnosed depressive disorders and subclinical levels of depressive symptoms
than do boys in early to middle adolescence (Angold et al., 1998; Ge, Conger, Lorenz,
& Simons, 1994; Laitinen-Krispijn, van der Ende, & Verhulst, 1999). In prepubertal
children (Tanner stage 1) disorders with hypomanic-manic symptomatology (Schraufnagel,
Brumback, Harper, & Weinberg, 2001) and seasonal affective disorders (Swedo
et al., 1995) were more common, whereas in pubertal-age adolescents (Tanner stages
3-5) there was a predominance of depressive symptomatology. Other studies found no
association between prepubertal and early-adolescent bipolar disorder (Geller et al.,
2000). Overall, results are inconclusive regarding the connections between puberty and
psychopathology. A major deficit in the literature is that few longitudinal studies of
adolescent psychopathology employ state-of-the-art indexes of pubertal development,
such as Tanner stage and hormone concentrations.

Hormonal Control of Puberty

The hormonal regulation of growth becomes increasingly complex just before and with
the onset of puberty. Adequate levels of thyroid hormone and cortisol continue to be
prerequisites for normal growth, but the gonadal steroid hormones now play an increasingly
major role. There is also a dramatic activation of the GH/IGF-I axis. During
adolescence the gonadal steroid hormones and the GH/IGF-I axis continue to
exert independent effects on growth, but the interaction between them underlies the
dramatic alterations in linear growth velocity and body composition, including the regional
distribution of body fat.
Pulsatile gonadotropin secretion occurs at all ages, but puberty is heralded by an increase
in the amplitude of luteinizing hormone (LH) and follicle-stimulating hormone
(FSH) secretion, detectable even before the first external signs of pubertal development
are evident. This stage represents a reawakening of the state of the gonadal axis operative
during the late fetal and very early neonatal stages. Initially, biologically relevant
surges of LH occur predominantly at night, resulting in elevations of gonadal steroid
hormone concentration early in the morning. These then wane during the day as these
small but relevant levels of gonadal steroids reduce the levels of the gonadotropins because
the negative feedback remains operative at the very sensitive prepubertal stage.
With continuing maturation of the HPG axis (i.e., becoming relatively less sensitive to
the negative feedback of the gonadal steroid hormones), enhanced pulsatile LH release
occurs throughout the waking hours as well, resulting in more stable elevations of the
gonadal steroid hormones. The rising levels of these hormones promote the development
of secondary sex characteristics and the changes in body composition and the regional
distribution of body fat noted during pubertal development. Gonadal steroid
Biology of Puberty 21
hormones, primarily estradiol in both genders, also enhance bone mineral accrual and
affect adult height by promoting epiphyseal fusion.
A dramatic activation of the GH/IGF-I axis occurs during early- to midpuberty. The
rise in the mean 24-hour GH levels results from an increase in the maximal GH secretory
rate (pulse amplitude) and in the mass of GH secreted per secretory burst (Veldhuis
et al., 2000). The differential increase in GH secretion between boys and girls at
puberty follows the pattern of change in growth velocity. Girls show a significant rise in
circulating GH levels beginning at Tanner breast stage 2, with the highest levels found
at Tanner breast stage 3–4. An increase occurs later in boys, peaking at Tanner genital
stage 4 (Martha, Gorman, Blizzard, Rogol, & Veldhuis, 1992). During midpuberty the
day-night rhythm is obscured because of a greater rate of rise in secretory amplitude
during the day than the night (Martha et al., 1992). By the time adolescent development
is complete, the levels of GH and IGF-I decrease to nearly prepubertal levels in both
genders.
Clinical observations have shown that both GH and sex steroid hormones must be
present for normal pubertal growth. Individuals with a selective deficiency of either
hormone (e.g., hypogonadotropic hypogonadism or isolated GH deficiency) have an
attenuated pubertal growth spurt (Aynsley-Green, Zachmann, & Prader, 1976; Liu,
Merriam, & Sherins, 1987). Many of the growth-promoting actions of the gonadal
steroid hormones are mediated through the estrogen rather than androgen receptor, either
by direct secretion of estrogen or conversion of androgens to estrogens by peripherally
located aromatase. Individuals with complete androgen insensitivity demonstrate
that androgens are not necessary to support normal adolescent growth or to
achieve pubertal levels of GH and IGF-I if sufficient levels of estrogen are present
(Zachmann et al., 1986). Estrogens are responsible for skeletal maturation and fusion
of the epiphyseal plates.
Adrenarche
Adrenarche refers to the activation of adrenal androgen production from the zona
reticularis. These androgens produce pubic and axillary hair (pubarche) as well as body
odor, oily skin, and acne. Adrenarche stems from a poorly understood activation of the
HPA axis for androgen production, separate and distinct from the usual activation of
the HPA axis for cortisol production. There is a progressive increase in circulating levels
of dehydroepiandrosterone (DHEA) and its sulfated form (DHEAS) in both boys
and girls beginning by age 7 or 8 years and continuing throughout early adulthood before
declining with advancing age.
The exact mechanism responsible for the onset of adrenarche is controversial, although
recent evidence suggests that adrenocorticotropic hormone (ACTH; Weber,
Clark, Perry, Honour, & Savage, 1997) and/or 3-hydroxysteroid dehydrogenase play a
significant role in the regulation of adrenarche (Gell et al., 1998). Adrenarche only recently
began to be studied in relation to psychological development (Dorn, Hitt, &
Rotenstein, 1999), as discussed later.
Leptin and Puberty
Discovery of the hormone leptin led to the theory that it may be a signal allowing for
the initiation of and progression toward puberty (Mantzoros, Flier, & Rogol, 1997). An
22 Puberty and Psychological Development
alternative perspective is that leptin is implicated in the onset of puberty but may not
be the cause of the onset. Leptin is 16-kDa adipocyte-secreted protein, a product of the
obesity (ob) gene. Serum leptin levels reflect mainly the amount of energy stores but are
also influenced by short-term energy imbalance as well as several cytokines (indices of
immune system function) and hormones. Leptin is implicated in the initiation of puberty,
energy expenditure, normal menstrual cycles, fertility, maintenance of pregnancy,
and nutrition. Specifically, leptin may well be one of the messenger molecules signaling
the adequacy of the fat stores at puberty for reproduction and maintenance of pregnancy
(Kiess et al., 1999). The possible mechanism involves leptin as a hormone that
serves to signal the brain with information on the critical amount of fat stores that are
necessary for luteinizing hormone-releasing hormone (LHRH) secretion and activation
of the HPA axis. Moreover, circadian and ultradian variations of leptin levels are
also associated with minute-to-minute variations of LH and estradiol in normal women
(Mantzoros, 2000). The mechanisms by which leptin regulates body weight, adiposity,
and the hormones that increase at puberty (e.g., testosterone and estrogen) are not yet
known.
Leptin is higher in girls than in boys controlling for adiposity (Blum et al., 1997). At
the initiation of puberty, circulating leptin concentrations diverge in boys and girls. In
boys, leptin concentrations increase and then markedly decrease to prepubertal concentration
levels in late puberty. In contrast, in girls there are increasing concentrations
at puberty (Roemmich & Rogol, 1999). The increase in leptin is believed to result from
different alterations in the regional distribution of body fat in boys and girls at puberty.
Overall, sex differences in leptin concentrations are accountable to differences in the
amounts of subcutaneous fat in girls and greater androgen concentrations in boys
(Roemmich, Clark, Berr, et al., 1998). The biological effects of leptin in adult humans
are still to be determined, but reports show that congenital leptin deficiency leads to hyperphagia
and excessive weight gain from early infancy onward as well as failure of pubertal
onset in adolescence (Ong, Ahmed, & Dunger, 1999). Leptin concentrations
have not yet been examined in relation to behavior changes at puberty, but leptin provides
a promising biological probe for understanding pubertal processes and problems
of body image.