Book of the Month Evolutionary Psychiatry

A revolution neo-Darwinian theory .has transformed biology in the past few decades, using games theory and systems theory to push and extend Darwin's central insight to its limits, and illuminating whole areas of biology which were otherwise obscure. It is now clear why in social animals such as ants and bees there are individuals who are sterile and yet work for the good of the colony, or why many male animals will kill the young of other males of their own species; and the latter has enormous implications for understanding why child abuse is far more common in step-fathers. Perhaps the most important insight, encapsulated in Richard Dawkins' phrase, the selfish gene, is that the essential unit of natural selection is not the organism but the gene, the organism being seen merely as a gene's way of making another gene. The intellectual core of the neoDarwinian approach is the idea of 'inclusive fitness'; fitness is not measured in terms of the survival of the individual organism but of the survival of the genes which that organism shares with others in the population. The enigma of altruism then makes simple Darwinian sense an individual will sacrifice itself if a sufficient number of other individuals carrying the same genes (i.e. its relatives) are