PRETEND GENES 51Environments and Horticulture
Again this model fl ies in the face of real ity. Hundreds of studies show that
environments cannot be broken down into ele ments with in de pen dent ef-
fects on form and variation; they are interrelated and depend on each other
in nonlinear ways. But then, as mentioned in chapter 1, both sides of the
nature- nurture debate are quite vague about the environment. Th ey oft en
complain about not being able to identify it, or at least those parts of it that
create variation in human per for mance. In a 1997 paper, leading twin re-
searcher Th omas Bouchard lamented that “in spite of years of concerted
eff ort by psychologists, there is very little knowledge of the trait- relevant
environments that infl uence IQ.”^11 Much the same applies to variation in
other aspects of human per for mance, such as school attainment.
Consequently, the environment in twin studies is defi ned only in very
broad and ambiguous terms. Perhaps it is hardly surprising that there
have been numerous reports of the limited infl uence of the family envi-
ronment on creating individual diff erences. I mentioned in chapter 1
how searches for the environment end in disappointment. But there is
little attempt to characterize them, anyway. Most investigators, implic-
itly or explic itly, fall back on the horticultural view of the environment,
as mentioned in chapter 1.
In subsequent chapters, I show how the environment has amazing
complexity, with deep hidden patterns or structure: indeed, it is structure
and not ele ments that provide the real information for development and
variation. And it operates at several diff er ent levels in the evolved systems
of living things with quite unpredictable consequences, mostly regardless
of the specifi c genes. But by then I will have moved far beyond this crude
strength/power model of intelligence, anyway.
Other Assumptions
Th e above are the most crucial assumptions of the standard behavioral
g e n e t i c m o d e l. Th ere are many other assumptions, all self- evidently false,
and in ways that can severely distort heritability estimates. Th e following
are just a few of them.
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