“The phrase ‘nature and nurture’ is a convenient jingle of words, for it separates under two distinct heads the innumerable elements of which personality is composed. Nature is all that man brings with himself into the world; nurture is every influence without that affects him after his birth.” The human genome experiment and the associated genetic mapping onto human diseases and characteristics have had wide ranging implications. Epigenetic factors are important regulatory mechanisms in the field of neurobiology, in particular, the neurobiology of attachment and sexual behaviour. Epigenetics also points to some important implications concerning mental representations and their influence on the expression of sexual and attachment behaviour among juvenile sex offenders. Research into the neurobiological effects of psychotherapy could also challenge the notion that neurobiological dysfunction can only be ameliorated by psychopharmacology. The discovery of the social brain and related findings concerning the automaticity of higher mental processes has caused a Galilean-like revolution in the view of human thinking.