The Evolutionary Psychology FAQ

Edward H. Hagen, Institute for Theoretical Biology, Berlin

Is evolutionary psychology another form of genetic determinism?

Yes and no. Definitely no if one is referring to behavioral genetics. All organisms, including humans, can be conceived as an integrated set of functional parts. Hearts, lungs, eyes, blood, bones, muscles, veins, kidneys, livers, skin, intestines, gonads, and the immune system all perform specific functions. Modern medicine is founded on this functional view of the body. In the parlance of evolutionary biology, these functional parts are called adaptations. Adaptations arise through a process of evolution by natural selection. Evolutionary psychology argues that natural selection acts on nerve tissue (or, if you prefer, on the genes that code for nerve tissue) the same way it does on every other type of tissue. Therefore the brain should be organized just like the rest of the body, as an integrated set of interacting adaptations. In fact, there is no fundamental distinction between physiological adaptations and psychological adaptations. Although the process whereby genetic information directs the development of bodily functions is still largely opaque, there are very compelling empirical and theoretical reasons to believe that there are genes for arms, legs, lungs, etc. Because all humans (with very rare exceptions) have arms, legs, lungs, etc., that are built the same way and have the same features, we can surmise that we all share essentially the same genes for these limbs and organs. The universal architecture of the body is genetically determined in this sense. Since psychological adaptations like vision and pain are no different from other adaptations in this regard, they, too, are genetically determined human universals.

However, this is not what is usually meant by 'genetically determined.' Often, researchers propose a genetic basis for criminality, alcoholism, anti-social behavior, schizophrenia, heart-disease, what-have-you. In other words, a genetic basis is postulated for individual *differences,* not similarities. In general, evolutionary psychology is not concerned with individual genetic differences. Genetic differences between individuals are known to be quite minor compared to our genetic commonalties. As will be explained in more detail in the next section, the genetic basis for the functional organization of our bodies and brains must be shared by all humans. In the same way that physiologists want to know how the body works, evolutionary psychologists want to understand how the brain works. Although there are no doubt minor differences in heart morphology that have a genetic basis, all hearts are built and function in exactly the same way. Similarly, psychological adaptations, should they exist, must also be built and function in the same way across individuals, although there will, no doubt, be minor differences attributable to underlying genetic differences. An evolutionary psychological approach to individual differences that does not rely on genetic differences will be detailed in a future version of the FAQ.

Copyright 1999-2002 Edward H. Hagen