"Since 1978, when a pail of water was dumped over my Harvard friend E. O. Wilson for saying that genes influence human behaviour, the assault against human behavioural genetics by wishful thinking has remained vigorous. But irrationality must soon recede. It will soon be possible to read individual genetic messages at costs which will not bankrupt our health systems. In so doing, I hope we see whether changes in DNA sequence, not environmental influences, result in behaviour differences. Finally, we should be able to establish the relative importance of nature as opposed to nurture."