PRETEND GENES 69assumptions, estimates are “guaranteed to be biased.” Th ey conclude
that “results obtained using GCTA, and the results’ qualitative interpre-
tations, should be interpreted with great caution.”^41
In other words, the method seems to be only good for redescribing
the history of the class structure of society. As Charney says, “Th is state of
aff airs (not at all unique to the UK)... is fertile ground for spurious heri-
tability estimates.” In the same paper, he concludes that the GCTA search
for thousands of ge ne tic variants of tiny eff ect “is the last gasp of a failed
paradigm.”^42
Yet now, as before, far from reviewing assumptions in their method,
investigators call for bigger and more expensive research in the same
vein. I explain the deeper conceptual reasons for their prob lems in the
chapters that follow. Let us complete this chapter by clearing up a few
simpler misunderstandings.
MISUNDERSTANDING OF HERITABILITY
AND MISLEADING TERMINOLOGYTh e concept of heritability, as used by behavioral ge ne ticists, is oft en
taken to be the converse of malleability: for example, that individual
diff erences in a trait with higher heritability are quite fi xed, and the
“ge ne tic” ranking will persist what ever the environmental conditions.
Th is harks back to the fatalism and pessimism about human potential
mentioned in chapter 1. For example, Dalton Conley and colleagues
expect that reduced heritability estimates might “suggest that many
traits might be more socially malleable than previous research... would
suggest.”^43
Th is is a widespread misconception, because there is no relation be-
tween heritability and malleability in a trait. Heritability says nothing
about rankings under diff er ent environments. Heritability is about asso-
ciations between variation (or variance), not identity and causation. A
condition like phenylketonuria has a heritability of 1 ( there is perfect cor-
relation between ge ne tic and phenotypic variation). But the condition is
relieved by a simple environmental treatment (removing the amino acid
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