A POSITIVE CONCLUSION 357
therefore have a genetic basis, since natural selection cannot operate
in the absence of genetic variation. Sociobiologists have tried, for
example, to identify an adaptive and genetic foundation for
aggression, spite, xenophobia, conformity, homosexuality,* and
perhaps upward mobility as well (Wilson, 1975).
I believe that modern biology provides a model standing
between the despairing claim that biology has nothing to teach us
about human behavior and the deterministic theory that specific
items of behavior are genetically programed by the action of natu-
ral selection. I see two major areas for biological insight:
- Fruitful analogies. Much of human behavior is surely adap-
tive; if it weren't, we wouldn't be around any more. But adaptation,
in humans, is neither an adequate, nor even a good argument for
genetic influence. For in humans, as I argued above (p. 324), adap-
tation may arise by the alternate route of nongenetic, cultural evo-
lution. Since cultural evolution is so much more rapid than
Darwinian evolution, its influence should prevail in the behavioral
diversity displayed by human groups. But even when an adaptive
behavior is nongenetic, biological analogy may be useful in inter-
preting its meaning. Adaptive constraints are often strong, and
some functions may have to proceed in a certain way whether their
underlying impetus be learning or genetic programing.
For example, ecologists have developed a powerful quantitative
who believes that biological evolution is not irrelevant to human behavior, then I
suppose that everybodv (creationists excluded) is a sociobiologist. At this point, how-
ever, the term loses its meaning. Human sociobiology entered the literature (profes-
sional and popular) as a definite theorv about the adaptive and genetic basis of
specific traits of human behavior.
*Lest homosexuality seem an unlikely candidate for adaptation since exclusive
homosexuals have no children, I report the following story, advocated by E. O.
Wilson (1975, 1978). Ancestral human society was organized as a large number of
competing family units. Some units were exclusively heterosexual; the gene pool of
other units included factors for homosexuality. Homosexuals functioned as helpers
to raise the offspring of their heterosexual kin. This behavior aided their genes
since the large number of kin they helped to raise held more copies of their genes
than their own offspring (had they been heterosexual) might have carried. Groups
with homosexual helpers raised more offspring, since they could more than bal-
ance, by extra care and higher rates of survival, the potential loss by nonfecundity
of their homosexual members. Thus, groups with homosexual members ultimately
prevailed over exclusively heterosexual groups, and genes for homosexuality have
survived.