Conceptions of adult personality development have
evolved out of two very different traditions in psychology;
clinical psychology and life-span developmental
psychology. The approaches and the findings
about systematic change in adulthood reflect these
different paradigmatic approaches to the study of
lives. Due to considerable overlap between studies of
individual differences and clinical psychology, many
of the oldest and most influential theories of personality,
most notably psychoanalytic psychology but
also ego psychology and interpersonal psychology,
were developed based on clinical observations of
patients. Although strikingly different in its basic
tenets, social cognitive theory of personality also
evolved out of close connections between clinical and
personality psychology, essentially addressing differences
between normal and abnormal processing involved
in basic psychological functioning. Thus, the
oldest approaches to personality were tied closely to
understanding psychopathology.
In contrast to the traditional individual difference
approach, life-span psychology was born only in about the 1970s and reflects the view that human development
is a continuous adaptive process (Baltes and
Goulet 1970). Life-span psychology aims to identify
and illuminate normal developmental changes in all
areas of psychological functioning, including but not
limited to personality, from birth until death. Perhaps
most notably, life-span psychology is distinguished by
the presumption that human growth is at no time
during the life course complete. Consequently, the
different presumptions inherent in the two approaches
direct attention to different research foci. Whereas
traditional adult personality psychologists ask
whether traits acquired in childhood persist across
adulthood, whether particular personality crises
present themselves at particular stages of life, or how
personality disorders are transformed in later life, lifespan
psychologists are more likely to target specific
age-related issues, like whether people grow wiser with
age, whether conceptions of the self grow more or less
complex over time, and whether self-regulatory processes
change in systematic ways over time. As noted
above, whether one finds evidence for stability or
change depends importantly on where one looks and
the particular questions one poses.
The next sections include a birdseye view of the
earliest approaches to personality development and
brief synopses of research on personality development
deriving from the trait approach to personality development
and from life-span developmental psychology.