Published online by Cambridge University Press: 13 June 2014
There has been increased interest recently in the implications of Darwinian theory on psychology, psychiatry and in medicine generally. As a result a large number of publications have appeared that attempt to reformulate a range of psychiatric disorders in the light of evolutionary theory. However, relatively little attention has been paid to the subject of suicide from the evolutionary perspective with some notable exceptions. The purpose of this brief paper is to bring the Darwinian perspective to the notice of a wider psychiatric readership hoping that this will add a further dimension to the debate on suicide and selfdestructive behaviour. Darwinia n theory had found it difficult to account for the existence of altruistic behavioural strategies in social animals until it was explained by Hamilton that the focus for selection was not the individual but the gene. Altruism here refers to any behaviour that reduces the reproductive fitness of the donor while increasing the reproductive fitness of the recipient. According to Hamilton's formulation (the kin selection theory) the individual will behave in a nepotistic manner (ie. altruistically towards kin) as this will enhance the overall chances of his genes to pass to the next generation not only through his own descendants but through non-descendant kin, a measure he termed ‘inclusive fitness’. Therefore it would not be surprising that individuals would be more likely to behave altruistically towards kin than non-kin.