PRETEND GENES 37ences are not based on real genes (or environments), but on imaginary
models of them. No one can actually “see” the genes implicated by Burt
and his heirs. We cannot count them or “weigh” them, mea sure their
“charge,” or other wise grade them. Nor can we work out who has what
permutations, with what eff ects (except in rare disorders). No one is able
to prove the causal consequences of having these genes in properly con-
trolled experiments (as the best science, in other fi elds, does).
Instead, behavioral ge ne ticists resort to statistical models. Of course,
such models can be useful in virtually every fi eld of science (I have used
them myself many times). But the conclusions we wring from such models
are only as good as the assumptions that go into them. Th ere is a well- worn
joke about the “spherical cow” or “spherical horse” prob lem (it is told in
many versions). Here is one: A physicist loudly claimed he could predict the
winner of any horse race with great accuracy; but, he said more quietly,
only if it was a perfectly elastic, spherical horse, carry ing a fi xed weight, and
moving through a vacuum at fi xed speed over an even surface.
Th e models used by virtually all behavioral ge ne ticists to tell us about
the importance of genes in human potential are highly debatable in that
sense. Th ey are based on highly simplifi ed assumptions about genes,
about environments, about the nature of intelligence and its development,
and about describing and mea sur ing individual diff erences in it. Since it
is not diffi cult to show that the assumptions are false, it follows that the
models are far removed from the real ity of the development of form and
individual diff erences in human intelligence.
It is impor tant to examine all the assumptions and expectations of the
model in turn. Let us start with the peculiar model of the gene that is used
to produce such impor tant claims, with the socially profound implica-
tions just mentioned.
MENDELIAN GE NE TICSCharles Darwin emphasized the role of heredity in human variation and
evolution. But he still did not know what the hereditary material, passing
from parents to off spring and infl uencing their variation, consisted of.
He rather vaguely thought it was some kind of germplasm that became
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