ABSTRACT
Hans Eysenck has done more than anyone to promote the necessity for those interested in behaviour to take a serious interest in genetics. He has railed against the concept of the ‘typical individual’, arguing cogently that the best way to understand mechanisms is to study differences. This has long been recognized by geneticists. Thus, when Beadle and Ephrussi (1937) wished to understand the physiology of eye colour determination in Drosophila, they started with mutant individuals having eye colours different from normal (or ‘wild type’). By crossing them in various configurations they were able to deduce the biochemical pathways responsible for eye colour. They later applied this paradigm to a much wider array of metabolic processes in the bread mould Neurospora (Beadle and Tatum, 1941), and in a short time others applied it to bacteria and their viruses. To this paradigm, which is but an extension of Mendel’s experiments in his pea garden, can be attributed the scientific revolution which in only thirty years or so has revealed the structure of DNA, the mechanism of protein synthesis and now even the nucleotide sequences of genes responsible for major clinical disorders. Within two years or so, perhaps even by the time this book is published, we expect to know sequences for the genes responsible for Huntingdon’s chorea and Duchenne’s muscular dystrophy, an advance unimaginable even ten years ago.
