From an evolutionary standpoint, individuality, self-awareness,
and self-serving behavior all appear to be by-products of our species'
tremendous dependence on learning. Learning, by its very nature,
is a differentiating and individuating experience. No two individuals
can possibly share exactly the same set of experiences over the courseof
their lives, and since eperience shapes both our values and our perceptions
of ourselves, a highly developed awareness of self and self-serving behavior
become unavoidable. This does not prevent us from cooperationg with
one another since most of us discover in infancy and early childhood that
the benefits of cooperation usaully exceed the costs. Thus, enlightened
self-interest ensures a substantial amount of cooperation in every human
society (1991, p. 26).