358 THE MISMEASURE OF MAN
theory, called optimal foraging strategy, for studying patterns of
exploitation in nature (herbivores by carnivores, plants by herbi-
vores). Cornell University anthropologist Bruce Winterhalder has
shown that a community of Cree-speaking peoples in northern
Ontario follow some predictions of the theory in their hunting and
trapping behavior. Although Winterhalder used a biological theory
to understand some aspects of human hunting, he does not believe
that the people he studied were genetically selected to hunt as eco-
logical theory predicts they should. He writes (personal communi-
cation, July 1978):
It should go without saying... that the causes of human variability of
hunting and gathering behavior lie in the socio-cultural realm. For that
reason, the models that I used were adapted, not adopted, and then
applied to a very circumscribed realm of analysis.... For instance, the
models assist in analyzing what species a hunter will seek from those avail-
able once a decision has been made to go hunting [his italics]. They are, how-
ever, useless for analyzing why the Cree still hunt (they don't need to),
how they decide on a particular day whether to hunt or join a construction
crew, the meaning of hunting to a Cree, or any of a plethora of important
questions.
In this area, sociobiologists have often fallen into one of the most
common errors of reasoning: discovering an analogy and inferring
a genetic similarity (literally, in this case!). Analogies are useful but
limited; they may reflect common constraints, but not common
causes.
a. Biological potentiality vs. biological determinism. Humans
are animals, and everything we do is constrained, in some sense, by
our biology. Some constraints are so integral to our being that we
rarely even recognize them, for we never imagine that life might
proceed in another way. Consider our narrow range of average
adult size and the consequences of living in the gravitational world
of large organisms, not the world of surface forces inhabited by
insects (Went, 1968; Gould, 1977). Or the fact that we are born
helpless (many animals are not), that we mature slowly, that we
must sleep for a large part of the day, that we do not photosyn-
thesize, that we can digest both meat and plants, that we age and
die. These are all results of our genetic construction, and all are
important influences upon human nature and society.
These biological boundaries are so evident that they have never