Our understanding of the interrelationship of genetic predisposition, experiences in the first 3 years of life and psychological disturbance in later development is currently in something of a flux. We are all mesmerized by the rapid unfolding of scientific understanding concerning the genetic transmission of disease. This has raised the welcome possibility of a cure-gene therapy-for many deadly and painful illnesses and disabilities. ‘Genomics’, the process of identifying the specific function of individual genes, has become the best-funded and most aggressively pursued subject in the field of biology and medicine. In the behavioural and social sciences the influence is also beginning to be felt; unfortunately principally detracting from its standing in models of disease causation. The discovery of genetic influences appears to have profoundly undermined interest in the psychological and the social and strengthened an already powerful move towards biological reductionism. The shifts in implicit and explicit scientific understanding to favour genetic determination of psychological problems and characteristics has begun to impact on all our attitudes towards the psychological as a pivotal causal influence and an appropriate level of analysis for the understanding of mental disorder.