Search for ‘Michael Rossi’ (1 article found)
The predilections of twins
The verdict that genes matter, but so does environment, seems obvious. That might, as Segal argues, be because of our increasing acceptance of genetic explanations of behaviour – brought about in no small part by Mistra itself – or it might be the effect of attempting to weigh the contributions of two already overdetermined quantities, genetics and environment, to another overdetermined quantity, general behaviour. Indeed, one comes away from Born Together – Reared Apart with the impression that the flexibility of genes as go-to causal mechanisms for almost any particular individual behaviour impeaches rather than reinforces their explanatory power. With a little creativity, a just-so story can link seemingly any behaviour to genes, provided one doesn’t have to specify the genes in question, or think too closely about the behaviour. For instance, Segal presents the case of two identical twins, both ‘extremely talented in mathematics’. One of them, raised in China with little education, found work as a cashier; the other, raised in the US, ‘obtained an advanced science degree’. Segal treats this as evidence of identical genes expressing themselves in the face of different environmental circumstances, but the explanation raises more questions than it answers. Does one use the same ‘quantitative skills’ as a cashier and as a scientist? What, precisely, are the cognitive processes involved in ‘mathematics’? For that matter, what conditions (meritocratic, bureaucratic, personal etc) affect job selection in China as against the US, and how is the expression of genes for mathematical ability affected by them? From this and other examples of ostensibly genetically driven twin behaviour, one is left with the impression that we wouldn’t be much worse off assigning personal differences in behaviour to the levels of cheerfulness factor in germ plasm.
There is further cause for concern. Mistra’s inventories encoded a surprising array of complex, highly individuated behaviours by means of standardised, uni-dimensional measures. For instance, fascinating as it is to learn that a vague, complicated and subjective trait such as ‘conservatism’ is genetic in origin, it’s even more interesting to learn that there’s a psychological metric – the ‘Wilson Patterson Conservatism Scale’ – that Mistra researchers used to measure it. But what, precisely, is it that the conservatism scale measures, and why should we take Wilson and Patterson’s version of conservatism as the official definition? The psychologist Barrie Stacey wrote in 1978 that the W-P conservatism scale appears to have ‘three major components – blimpish religiosity, racialism and a rather prurient sexuality’. These, in his view, ‘add up to a greatly constricted view of conservatism’. Whose conservatism is the one reflected in our genes: Wilson and Patterson’s? Stacey’s? Both? Neither? Segal’s circular explanation, that the conservatism scale captured a subject’s conservatism, does little to clarify the matter. The same can be said of numerous other Mistra measures, including religiosity, creativity, leisure time activity, intelligence and mathematical skill: these are not natural kinds, but social kinds – social values which we identify by names (like ‘conservatism’) for convenience in colloquial conversation. Segal dismisses such concerns with a terse note that the ‘intelligence tests, personality inventories and most of the interest questionnaires that were administered had been used widely in prior research. The reliability and validity of these instruments had been well established.’ Perhaps, but when what’s at stake is the cause of human behaviour, and therefore the extent of biological influence on such social issues as education reform, economic inequality, unemployment, crime and sexuality, one could wish for closer scrutiny of the means used to demonstrate that genes ‘explain’ behaviour.
