Given that evolutionary psychology and molecular neuroscience are both relatively recent fields and that both study what is going on in our head, there seems to be fairly little interplay between the two subjects. In their review article, Pankseep et al. attempt to rectify this dearth of collaboration.
The authors concede two crucial points that evolutionary psychology has given to the scientific community: the idea there is a some core human psyche that is a product of our sociobiological evolution, and the correct predictions that it has made in understanding our current mental processes. However, some evolutionary psychologists may go too far in presupposing that our reward system itself is unique, as it was probably co-opted from a shared ancestor of mammals in evolution and adapted to fire to general symbols instead of specific signs. I’m not sure if this is a straw man argument that they are presenting, but if it is not, it deserves serious attention.
Furthermore, many of the social processes regulated by the hypothalamic-pituitary-adrenal axis are seen in other animals as well. For example, consider the “resident-intruder” paradigm common in studies of rats. In these studies, the intruder is almost always the “loser” of the social interaction and very commonly exhibits physiological changes following this defeat. These include loss of weight, testicular regression, and increased fearfulness. The changes are especially evident when the “loser” rat is not placed back in a social housing condition but is instead housed in isolation. It is quite evident that humans are not the only intensely social animals, so why should we limit our study to them?
With this groundwork in play, the authors present what they term the “seven deadly sins of evolutionary psychology”:
1) The assumption that the neocortex is the primary region for human differentiation from other animals may be foolhardy since the system is maintained between mammalian species. Perhaps some of the differentiation emerged epigenitically because of cultural changes?
2) An overemphasis on one species, when others have useful insights to yield as well.
3) They may focus too much on the specifics and miss the general point. What are the general processes that could have evolved that could account our current psychological state?
4) Since the idea of “brain centers” was cast aside a few decades ago, evolutionary psychologists must explain how their ideas fit within an integrated brain.
5) Too often conflating emotions–the will to do something–with reasoning-based decisions. Although they are closely related, there may be a way to distinguish between the two and note where evolutionary adaptations have developed as emotions, and where they have developed as decision making skills.
6) There is no need to ignore the brain, since molecular neuroscience is providing a solid base upon which others can build. They generalize this criticism to all social scientists.
7) Declaring a mental process to be an “algorithm” is silly, because more and more research suggests that the brain does not work with this sort of distinct processes. Although they can be useful as models, ultimately the best models will discuss an integration with the rest of the brain processes. Again, this criticism could be reasonably applied to just about anyone, and probably has more to do with the current system of science than any one researcher’s desire to specialize.
The authors then go on to discuss how some of these “sins” can be resolved through a study of molecular genetics and neuroscience. These demands on evolutionary psychologists are challenging, but if they meet half of the demands of their toughest critics, it will probably be enough for the rest of the scientific community.
Panksepp J, Moskal JR, Panksepp JB, Kroes RA 2002 Comparative approaches in evolutionary psychology: molecular neuroscience meets the mind. Neuroendocrinology Letters 23: 105-115. pii:NEL231002R11.