Abstract

Journal of medical ethics, I982, 8, 96-9g Words about their liberal credentials: 'There are now so many and nurture Nature lines of evidence for substantial heritability . . . that, in of substantial bias in most of them, it is unlikely spite David Papineau Department ofHistory andPhilosophy that all are misleading' (i). University of Science, Cambridge What converted sceptics do insist on, though, many care with the precise meaning of 'heritability'. Actual is Do genes influence intellectual abilities? A lot of estimates for the heritability of IQ scores in numerical find this question somehow objectionable. people Britain and the USA between 20 per cent Great range are prepared to address it at all, they are Insofar as they 8o cent. What do such numbers mean? and per to extremely suspicious of any arguments for likely be One might naturally enough suppose that they indi- the hereditarian position. They feel there is something cate the average contribution that genes make to IQ improper, something almost tasteless, about the idea scores for instance one might say that per cent of (as I5 that intellectual abilities derive from genes. (Many personal income in the UK consists of unearned such people took their