Environment    Among the factors that exert pressures on our personality for-
mation are the culture in which we are raised, our early conditioning, the
norms among our family, friends, and social groups, and other influences that
we experience. The environment to which we are exposed plays a substantial
role in shaping our personalities.
      For example, culture establishes the norms, attitudes, and values that are
passed along from one generation to the next and create consistencies over
time. An ideology that is intensely fostered in one culture may have only mod-
erate influence in another. For instance, North Americans have had the themes
of industriousness, success, competition, independence, and the Protestant
work ethic constantly instilled in them through books, the school system, fam-
ily, and friends. North Americans, as a result, tend to be ambitious and aggres-
sive relative to individuals raised in cultures that have emphasized getting along
with others, cooperation, and the priority of family over work and career.
      Careful consideration of the arguments favoring either heredity or envi-
ronment as the primary determinant of personality forces the conclusion that
both are important. Heredity sets the parameters or outer limits, but an indi-
vidual's full potential will be determined by how well he or she adjusts to the
demands and requirements of the environment.

Situation   A third factor, the situation, influences the effects of heredity and
environment on personality. An individual's personality, although generally
stable and consistent, does change in different situations. The varying de-
mands of different situations call forth different aspects of one's personal
ity. We should not, therefore, look at personality patterns in isolation.⁵
      It seems only logical to suppose that situations will influence an indi-
vidual's personality, but a neat classification scheme that would tell us the
impact of various types of situations has so far eluded us. "Apparently we
are not yet close to developing a system for clarifying situations so that
they might be systematically studied."⁶ However, we do know thatcertain
situations are more relevant than others in influencing personality.
      What is of interest taxonomically is that situations seem to differ
substantially in the constraints they impose on behavior. Some situa-
tions (e.g., church, an employment interview) constrain many behaviors;
other situations (e.g., a picnic in a public park) constrain relatively few.⁷
      Furthermore, although certain generalizations can be made about per-
sonality, there are significant individual differences. As we shall see, the
study of individual differences has come to receive greater emphasis in per-
sonality research, which originally sought out more general, universal patterns.