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Abigail Tuttle O’Keeffe
PEERS
See: ADOLESCENCE; FRIENDSHIP; SOCIAL DEVEL-
OPMENT
PERSONALITY DEVELOPMENT
Personality psychology is considered the study of in-
dividual differences in behavior—how individuals be-
have differently from one another in various
situations. Developmental personality psychologists
are interested in understanding the ways individuals
develop their unique patterns of responding to the
environment based on genetic endowments and so-
cial histories. Also of interest is identifying the ways
in which personality changes or is stable across devel-
opment, as well as identifying early behavioral pre-
cursors that are predictive of later individual
differences. From these multiple interests have come
a number of perspectives on personality development
relevant to the age period spanning infancy through
adolescence (birth to twenty years of age).
Perspectives on Personality Development
Behavioral individuality in newborns is defined as
temperament. A number of competing models of
temperament have been proposed, but most general-
ly view temperament as a construct that represents
the early emerging, constitutionally based, behavioral
individuality that is consistent over both time and sit-
uations. Conceptually, psychologists have differenti-
ated infant temperament from childhood and
adolescent personality by noting that temperament
represents the more biologically based basic emo-
tions, while personality represents the consistent be-
havioral repertoire developed by an individual out of
her interactions with the social environment.
The course of personality development from
temperamental beginnings has been described by
some as a transition from temperament to personality
or as an elaboration from basic dimensions of temper-
ament to more complex dimensions of personality.
By late childhood and adolescence, this behavioral
transition or elaboration is apparent as behavior has
become more purposefully directed and increasingly
incorporates concepts like self-understanding.
A number of theories have been developed that
outline different interactional processes of personali-
ty development, but most of the theories can be
grouped into two categories: those that emphasize
certain developmental environments in shaping an
individual’s personality and those that emphasize the
individual’s biology. A theoretical orientation that
emphasizes either the environment or biology gener-
ally does not completely discount the position of the
other, but rather stresses one factor over the other
with respect to relative importance.Attachment
Many personality theorists and researchers em-
phasize the importance to early personality develop-
ment of the quality of attachment between infant and
primary caregiver. Attachment is considered the en-
during emotional tie that an infant forms with his
caregiver, which helps to ensure a relationship style
between caregiver and infant that fosters infant sur-
vival. Several models characterize the developmental
progression of attachment formation. These models
emphasize the universal, biologically based process of
attachment as it unfolds across infancy and child-
hood.
Significant individual differences are not thought
to occur in the actual process of attachment formation
itself, but individual differences do occur in the quali-
ty or style of attachment. See Table 1 for a listing of
the commonly agreed upon infant and childhood at-
tachment patterns and their characteristic behaviors.
These patterns of behavior have been identified
through a laboratory procedure called the Strange
Situation, which was developed by Mary Ainsworth
and her colleagues. The Strange Situation is a stan-
dardized procedure that places the infant or young
child in increasingly stressful separation-reunion situ-
ations with the caregiver.
Many contributing factors lead to differences in
attachment style, but the developmental factor typi-
cally viewed as most important to attachment out-
comes is caregiver responsiveness to infant needs. For
example, a caregiver facilitates a secure attachment
by consistently meeting the infant’s needs. Infant
needs may be satisfied by behaviors such as respond-
ing to crying, feeding when hungry, physical contact,
and comforting during times of stress. If the infant’s
needs are met consistently, a secure attachment is300 PERSONALITY DEVELOPMENT