ABSTRACT
Genes and environment are inextricably intertwined. Old notions of the nature-nurture and brain-mind dichotomy have been supplanted by a rich web of synergistic relations between nature and nurture, soma and psyche. In attempting to address the nature-nurture debate, the two dominant psychological approaches of the last century – learning theory and psychoanalysis – agreed that experience with parents was pivotal in shaping the individual’s characteristics, values and dysfunctions in adaptation. Of the two approaches, psychoanalysis continued to emphasise that biologically inherited traits limited the changes that could be effected by socialisation and environmental influences (Freud, 1920). During the last decades of the twentieth century, quantitative behavioural genetic research1 eroded classical socialisation theories that emphasised the role of parenting and early family experiences (Scarr, 1992). The role of the environment was further eclipsed by the excitement of the human genome project and the promise that molecular genetics would uncover single mutated genes that caused specific behaviours and psychiatric disorders. Instead, epigenetics revealed that the environment can lead to heritable changes in gene expression in an organism, thus focusing anew on the important role played by the social environment in the final phenotype. Furthermore, molecular genetic methods uncovered even more complex and subtle mediators and moderators of gene-environment interaction in the pathways from genotype to phenotype. The individual’s subjective perception of the event or trauma has emerged as a potentially significant additional factor influencing the path from gene to behaviour. Thus, intrapsychic representational processes are not merely the consequences of environmental and genetic effects, but may be the critical moderators of these effects.
