begin in infancy—infants direct and respond to each
other’s smiles and vocalizations. As preschoolers age,
their interactions with peers become increasingly
complex, progressing from solitary play to onlooking
(child watches others but does not join), parallel play
(child plays beside but not with others), associative
play (child plays with others), and cooperative play
(child plays with others using coordinated roles). As
children age they engage in more of the latter forms
of play, though the former types of play are not en-
tirely abandoned. Moreover, the topics of play
change during childhood, from constructive play
(e.g., block building) to dramatic play to games with
formal rules.
This increased complexity of play is paralleled by
increased complexity of social behavior. This, as well
as the increased time spent with peers, has led psy-
chologists to focus much of their attention on the peer
relations of children and adolescents. Topics of study
include children’s acceptance or rejection by the larg-
er peer group, friendships, and aggressive and proso-
cial behaviors toward others. Researchers have also
examined gender differences in each of these aspects
of development.
The terms ‘‘popularity’’ and ‘‘rejection’’ are used
to describe the degree to which children are liked or
disliked by their peers. Certain types of behavior are
consistently related to group acceptance throughout
childhood. Popular children, who are liked by many
of their peers and disliked by few, tend to be sociable,
often do well in school, and are generally not aggres-
sive. Rejected children, on the other hand, who are
disliked by many of their peers and liked by few, are
often aggressive or withdrawn, have poor social skills,
and do not do well in school. Despite these general-
izations about popular and rejected children, howev-
er, these groups are heterogeneous (i.e., children in
these groups vary in their characteristics and/or be-
haviors). Some children are rejected because their ag-
gressive, disruptive behavior is annoying to peers,
while other children are rejected because they are
timid and socially anxious. Children may be popular
by behaving prosocially, being academically compe-
tent, and being leaders, while other popular children
are aggressive or delinquent, but are seen as ‘‘cool’’
by their peers. Importantly, behaviors that are valued
or devalued by peers are dependent upon group
norms, which are influenced by surrounding societal
and cultural values.
Whereas friendships of younger children center
around concrete reciprocities (e.g., sharing toys) and
those of older children emphasize self-disclosure and
loyalty, friendships at all ages are based on mutual lik-
ing, reciprocity of positive behavior, and seeking the
other’s presence. Both having friends and the quali-
ties of friendships are predictors of later develop-
ment. For instance, having friends during childhood
predicts having romantic relationships in adolescence
and feelings of self-worth in adulthood, having sup-
portive friendships predicts academic achievement
during school transitions, and having protective
friends can reduce peer victimization. It must be re-
membered that friendships are defined by two mem-
bers, and the characteristics that make a child a
desirable friend to one peer may not make that child
desirable to another. Children tend to have friends
who are similar to them in demographic characteris-
tics (e.g., age, race, gender), academic abilities (e.g.,
intelligence, school achievement), and social behavior
(e.g., aggression, attachment styles). Not only do chil-
dren tend to form friendships with those who are sim-
ilar, but friends also tend to influence each other such
that they become more similar over time.
The frequency of aggressive behavior remains
fairly constant during childhood, but physical forms
of aggression (such as hitting and pushing) displayed
in younger children tend to be replaced with verbal
aggression (such as teasing and threatening) among
older children. Highly aggressive children are often
rejected by their peers, and aggressive behavior is
often associated with academic failure. Despite often
being rejected by the larger peer group, however, ag-
gressive children typically have as many friends as
nonaggressive peers, most commonly with other ag-
gressive children. These deviant friends reinforce the
child’s aggression, and, when combined with academ-
ic failure and the loss of socialization from main-
stream peers, may lead to later delinquency and
antisocial behavior. The experience of being the vic-
tim of peer aggression can lead to negative out-
comes—both personal (e.g., depression, anxiety, low
self-esteem) and interpersonal (e.g., rejection, few
friends)—which in turn further perpetuate peer
abuse. These consequences are not limited to the pe-
riod during which the child is victimized; chronic vic-
timization can lead to low self-esteem and depression
that persists into adulthood.
The frequency of prosocial behavior, behavior
meant to assist others, increases during childhood,
then remains relatively constant during adolescence.
Nancy Eisenberg and Richard Fabes suggested that
acts of prosocial behavior are based upon the devel-
opment of prosocial moral reasoning, which involves
increasing concern for others and ability to under-
stand their suffering. Across childhood, prosocial be-
havior is related to popularity, the presence of
friendships, and high quality friendships.
It is important to keep in mind that differences
exist between boys and girls. Boys tend to play differ-
ently and in larger groups than girls. Boys’ friend-378 SOCIAL DEVELOPMENT