The Evolutionary Psychology FAQ

Edward H. Hagen, Institute for Theoretical Biology, Berlin

Do selfish genes mean selfish people?

Not necessarily. Describing genes as selfish is an analogy that has nothing to do with our folk notion of selfishness. Adaptations evolve via the differential reproduction of alleles (different versions of the same gene). This means that one version of a gene (allele A) at a particular locus causes organisms bearing that version to have a different phenotype (body structure) than organisms bearing a different version of the gene (allele B) at the same locus. If organisms with phenotype A produce more offspring than those with phenotype B, allele A will increase in frequency in the population. Allele A is said to have 'out-competed' allele B. Thus, allele A is a 'selfish gene'--it increased its frequency at the expense of allele B. But, every adaptation in the body evolved in this manner! That means that the genes coding for your hair are just as 'selfish' as the genes coding for your fingernails, which are just as 'selfish' as the genes coding for your kneecaps! The same goes for psychological adaptations: the genes coding for vision are just as 'selfish' as the genes coding for memory, which are just as 'selfish' as the genes coding for muscle control.

There is a narrow range of psychological adaptations whose properties do correspond to our folk notion of selfishness. When critical resources are limited, organisms which are able to obtain adequate supplies of these resources will out-reproduce those that don't. Obtaining such resources will often involve direct conflict between organisms, such as fighting for food or mates. Genes that code for fighting abilities that would allow organisms possessing those genes to out-compete other organisms for scarce resources will increase in frequency. So, the fact that some resources are limited means that strategies like aggression are likely to evolve in many species. Psychological adaptations for aggression correspond to our folk notions of 'selfishness', but it should be noted that these adaptations evolved by the same process as every other adaptation. The genes underlying these adaptations are no more 'selfish' than are the genes underlying any other adaptation.

Copyright 1999-2002 Edward H. Hagen