Shinka Shinrigaku (Evolutionary Psychology)

This textbook is for the evolutionary psychology course offered at the Open University. Evolutionary psychology aims for a unified understanding of the human mind based on the idea of “evolution by natural selection.” In doing so, the discipline commits to a specific way of understanding; however, common misunderstandings often prevent us from appreciating the true implications of evolutionary thinking. One of the goals of this textbook is to resolve these misunderstandings.
 
A prevailing misunderstanding is that natural selection favors traits or actions “for the good of the species.” For example, an individual who emits an alarm call to warn other group members of the presence of a predator is possibly more likely to be killed because the alarm call attracts the predator’s attention. Although it may sound plausible that such self-sacrificing actions can evolve for the good of the species, it is completely incorrect.
 
This misunderstanding may have its root in another misconception concerning natural selection: evolution by natural selection refers to a process whereby genes that are advantageous for survival and reproduction increase, while genes that are disadvantageous decrease. Natural selection works on genes but not on an entire species. If alarm-callers, who carry these genes, are disadvantaged in terms of survival, the action (i.e., emitting alarm calls) cannot evolve, regardless of how useful it is for the entire species.
 
Evolutionary explanations necessarily identify “selfish” functions behind apparently “altruistic” behaviors. For example, alarm calls may be emitted only when kin members, who share the same genes with the alarm-callers, are present. If this is the case, genes for alarm calls can spread themselves in a population. In other words, alarm calls are self-serving from the gene’s point of view.
 
Such explanations cause another type of misunderstanding. It is easy to confuse ultimate explanations (i.e., functions of actions) with proximate explanations (i.e., mechanisms of actions). The evolutionary explanation (i.e., ultimate explanation) of alarm calls does not imply that the individual emitting the call is consciously aware of the function of alarm calls themselves (i.e., the effect that an action of emitting the call has on their genes). When we eat foods, we are driven by hunger but not by a selfish motive to enhance own survivability (and ultimately spread own genes more efficiently).
 
The last misunderstanding derives from the confusion of the ultimate and proximate explanations. If one “erroneously” considers that an action is caused by selfish motives, then an individual may blame evolutionary psychology by “erroneously” assuming that it justifies unethical selfish behaviors. This is incorrect given that “is” never implies “ought.” The fact that Homo sapiens evolved to move bipedally never justifies bipedal locomotion or, alternately, implies any moral impropriety of traveling by car or plane instead.
 
Throughout this essay, I have listed the various misunderstandings; you might have even found my style unappealing. However, it reflects my commitment to a specific way of understanding (i.e., evolutionary thinking). I hope that this textbook is clear in explaining the very specific way that the discipline of evolutionary psychology approaches the understanding of how the mind works.
 

(Written by OHTSUBO Yohsuke, Professor, Graduate School of Humanities and Sociology / 2023)