Genes for human personality traits

This article considers three major problems with the concept of genes for human personality traits: (1) uncertainty about what human personality is; (2) what we mean when we say there is a gene "for" a mental attribute; and (3) the complexity of interactions between genes and environment, and among the genes themselves. It then draws on examples from empirical human genetic studies by the author and his colleagues in order to suggest that the concept of genes for human personality traits nevertheless does have some validity, and also that we may be on the brink of discovering genes with major effects on human personality. This possibility, in particular its ethical aspects, has aroused some public concern. It is suggested that confidential information about an individual's genes does not differ in principle from other confidential information about him or her, and that the ability (currently theoretical) to affect genes and their expression, temporarily or permanently, does not differ ethically from our current ability to affect other aspects of an individual's physical and psychological functioning. Genes for potential offspring, contained in ova and sperm cells, constitute a special case.