Genetics and Human Behaviour: The Ethical Context
Conclusion
3.20 The complexity of human behaviour and the difficulties in understanding how genes are involved may seem overwhelming. There is wide agreement that genes do have an indirect effect on behaviour. However, some commentators have suggested that any attempt to understand the processes by which genes influence behaviour will certainly fail. We disagree. We consider that it is neither a theoretical nor a practical impossibility to identify genes that contribute to behavioural traits and to understand some of the mechanisms by which they do so. However, we note that terminology such as ‘a gene for X’ or ‘a set of genes for X’ is very misleading because it fails to convey the complexity of the role of genetic factors in causal explanations of human behaviour. Genes determine which proteins are made. They do not determine which behavioural or personality traits an individual possesses. Furthermore, the product of an individual gene will only very rarely be directly related to a complex behavioural characteristic. It will normally interact with many other genes and with many non-genetic factors, which means that the predictive capabilities of tests for any single or small number of genes will in general probably be quite limited. Nonetheless, the proteins that genes make and the way these affect our bodies and brains will be one part of an explanation of human behaviour.