Individual differences research in a postgenomic era

The 20th century began with the re-discovery of Mendel’s laws of heredity; the 21st century began with the Human Genome Project’s working draft of the human genome sequence. We are rapidly approaching a postgenomic era in which we will know the entire genome sequence and, most importantly to individual differences researchers, all the DNA variations in the genome sequence. These DNA polymorphisms are the source of hereditary influence and will revolutionise genetic research on individual differences. Although attention is now focused on finding genes for complex quantitative traits, the greatest impact on individual differences research will come after genes have been identified. The future of genetic research on individual differences lies in moving from finding genes (genomics) to finding out how genes work (functional genomics). Functional genomics is usually equated with bottom-up molecular biology at the cellular level of analysis. However, a top-down psychological level of analysis (behavioural genomics) is likely to pay off more quickly in diagnosing and treating and especially predicting and preventing societally important problems. Bottom-up and top-down levels of analysis of gene-behaviour pathways will eventually meet in the brain. The grandest implication is that DNA will integrate individual differences research across the life sciences.