Though it is an uncomfortable truth to recognize, it is
unlikely that fitness is unconditionally maximized by investing
energy in positive attention to others. Instead,
though an empathic cognitive style may be useful in the
whirl of social life, it may have costs in terms of exploitation
or inattention to personal fitness gains. Moreover,
sociopaths, who are low in agreeableness, may at least
sometimes do very well in terms of fitness, especially when
they are rare in a population (Mealey, 1995). The balance
of advantages between being agreeable and looking after
personal interests will obviously vary enormously according
to context. For example, in a small isolated group with
a limited number of people to interact with and a need for
common actions, high agreeableness may be selected for.
Larger, looser social formations, or situations in which the
environment allows solitary foraging, may select agreeableness
downward.