Evolutionary psychology makes use of a biologically informed approach (modern evolutionary perspective) to examine the human behavior as well psychological traits like language, perception and memory. Specifically, evolutionary psychology has the primary objective of identifying which human psychological traits can be attributed to natural selection. Buss (1999) points that cognitive psychology is similar to evolutionary psychology in the sense that they both agree that the human behavior is linked to internal psychological mechanisms; the only difference is that evolutionary psychologists propose that the internal psychological mechanisms are adaptations. According to Rose and Rose (2000), the adaptationist thinking is the main focus of evolutionary psychology in the sense that it makes use of the principles applied in evolutionary biology. In this regard, evolutionary psychologists maintain that the modular structure of the human mind is the same as that of the body, wherein different modular adaptations serve various functions. As a result, evolutionary psychology holds that most elements of the human behavior are attributed to psychological adaptations, which evolved with the aim of solving the recurring problems faced by human ancestors in their environments (Workman & Reader, 2004). Despite the adaptationist approach being the cornerstone of evolutionary psychology, it has drawn significant criticism, especially basing on the fact that evolutionary psychology is inherently biased towards adaptationism. This paper reviews the criticism of evolutionary psychology with regard to its adaptationist perspective and evaluates whether this evolutionary psychology can overcome this critique or whether it is doomed to fail.

Evolutionary psychology makes use of the theoretical perspectives outlined in evolutionary biology to have an understanding of the design of the human mind. Ryle (2005) asserts that the influence of evolutionary psychology has grown significantly in the last 20 years, especially among behavioral scientists as well as the public. However, many people are of the view that core assumptions of evolutionary psychology are somewhat extraordinary and radical. According to Workman and Reader (2004), evolutionary psychology perceives the human brain to be comprised of mainly adaptations. The fundamental precept held by evolutionary psychology is that the natural selection resulted in both morphological adaptations as well as psychological adaptations, which are common among human beings. In the light of this view, the adaptation refers to a mechanism that helped in solving a specific problem linked to the reproduction and survival during the ancestral past (Wilson, Dietrich, & Clark, 2003).

According to the principles of evolutionary biology, a functionally specialized adaptation occurred for all types of organismal tissues found in living things. For instance, consider the organs found in the human torso, wherein the heart has the main function of pumping blood, the intestines take out nutrients from digested food, and the human liver filters blood among others. It is evident that the adaptation in the human body is domain specific in the sense that it does extremely well in its individual function; however, it might be less helpful for other tasks. For instance, the pancreas does a good job in the hormone production, such as insulin, but it is not useful in other tasks such as processing oxygen. Similar patterns of observations can be derived for any form of the adaptation in the various species (Rose & Rose, 2000). The underlying argument is that the functionally specialized adaptation is the universal and default evolutionary design standard. In this regard, all that evolutionary psychology does is to make use of the default position in the sense that it holds the assumption that the default and universal evolutionary design principle can be applied to the human brain, just like the case of other tissues found in species (Ryle, 2005). Despite the fact that these might appear an extraordinary assumption to individuals, who are not used to the idea that the brain is also a product of evolution, there is no doubt that this is an ordinary assumption when viewed from the adaptationist perspective of evolutionary biology. In the last 20-25 years, evolutionary psychologists have gathered a substantial amount of evidence to affirm that their assumptions are indeed correct. Rose and Rose (2000) assert that this evidence points out that there are individuals with specialized psychological adaptations; for example, the selection of reproductive partners in numerous contexts; spotting and administering punishment to cheaters, especially in cooperative scenarios; the recognition of well-known human faces; selecting non-toxic and nutritive food; and avoiding disease among others. In addition, whereas each of the adaptations is exceptional in tackling problems associated with a particular domain, they are less helpful in other domains. For instance, none of the aforementioned adaptations would be principally helpful in other domains such as empathizing with peers, running away from non-human predators or staying away from high-fall places (Wilson, Dietrich, & Clark, 2003).

It is also imperative to acknowledge that in contrast with the common critique of adaptationism in evolutionary psychology, the adaptationist evolutionary biology, which is the basis of evolutionary psychology, does not presuppose that all traits are the result of adaptations (Buss, 1999). The assumption held by the adaptationist evolutionary biology is that most of the traits tend be non-adaptive; as a result, it is particularly interested in identifying the traits that are derivatives of adaptations. For instance, it is highly likely that nipples in males have no individual function; however, they exist as a derivative of selection for nipples found in females. Workman and Reader (2004) stress that since the inception of the “adaptationist program” during the 1960s, the primary objective of the adaptationist evolutionary biology has always been and still is to openly provide the criteria that would enable scientists to differentiate adaptive traits from non-adaptive traits.

Critics of adaptationism in evolutionary psychology always argue that evolutionary psychology has not produced experiments that can be used to differentiate likely adaptive bases of the human behavior from evolutionary mechanisms that are likely to be non-adaptive. According to Gould and Lewontin (1979), evolutionary psychology is different from other human behavior theories, such as cognitive psychology, in the sense that it argues that some mental traits are somewhat adaptive. According to critics, in evolutionary biology, a number of non-adaptive mechanisms that enable the evolution to generate behaviors observed in people today. For example, besides the natural selection, other processes can alter gene frequencies and create novel traits. A case in point is a genetic drift, which is defined as random effects attributed to the chance variation in the environment, genes or development. According to Gould and Lewontin (1979), evolutionary derivatives refer to traits not specifically designed to perform an adaptive function; nonetheless, they may benefit the organism and are perhaps species-typical. When describing traits that bring no adaptive advantage to the organism, but are likely to be transferred by the adaptive trait, Gould and Lewontin (1979) invented the phrase “spandrel” and not some of form adaptation as maintained by evolutionary psychologists maintain. According to Gould and Lewontin (1979), helpful psychological traits are not likely to be adaptations rather exaptations, which the authors define as traits that were developed for either other purposes or no functional roles at all, after which they were co-opted to suit their current roles. Exaptation can be of two forms, which include a co-opted adaptation and spandrel. The co-opted adaptation refers to a trait that developed as a form of adaptation for a single purpose, although they were utilized for another adaptive role. As a result, Gould and Lewontin (1979) suggested that the cognition in human beings could be explained by the “spandrel” in the sense that the natural selection increased the size of the human brain; however, most of the mental properties of human beings are spandrels (non-adaptive side effects associated with a developing structural complexity of such a magnitude). After a trait that has been acquired using other mechanisms results in the adaptive advantage (as claimed by evolutionary psychologists as the mental properties of human beings do), then Gould and Lewontin (1979) point out that it is open to the additional selection as a form of an “exaptation”. In this regard, critics of adaptationism in evolutionary psychology maintain that the adaptive significance of mental properties that are examined by evolutionary psychologists has not been affirmed. In addition, critics assert that the manifestation of such traits cannot be linked to the natural selection.

There is a number of problems associated with Gould and Lewontin’s criticisms (1979). First, evolutionary psychologists perceive adaptations as a form of the psychological phenomena, which are considered the main faculties of the human mind. Gould and Lewontin (1979) argue that the primary form of the psychological adaptation in human beings relates to the size of the brain. However, there was no adaptive advantage associated with the largeness of the brain by itself. As Buss (1999) illustrates, the sheer bulk of the human brain is perhaps disadvantageous. If anything is to be considered a by-product or derivative, then it must be the brain size of humans, since it consumes most of the body’s nutrients; for instance, the brain takes up 18 percent of the energy intake despite being only 2 percent of the total body weight (Ryle, 2005). In addition, the human brain makes people highly vulnerable to falls and blows and increases hazards incurred during childbirth. Evidently, it can be argued that the bulkiness of the brain is perhaps a derivative of the selection process for more complex and computational abilities; this enabled human ancestors to deal with the natural world, hand bog tools and deal with one another. Therefore, the critics’ assertion regarding what constitutes a psychological adaptation, used to differentiate by-products from adaptations, can be argued to be getting things backwards. This is because the capacities facilitated by a larger brain size are considered some form of the adaptation, because the selection served to address these capabilities, whereas the sheer brain size can be considered a derivative for the selection process for these capabilities.

Fundamentally, it is evident that evolutionary psychology attempts to highlight the selected-for capacities associated with an enlarging brain size. In this regard, Wilson, Dietrich and Clark (2003) assert that evolutionary psychology appears faultless. Certainly, it does mean that each of the psychological mechanisms outlined in evolutionary psychology is, in fact, a form of the adaptation. In addition, this does not mean that evolutionary psychology has accurately recognized any of the existing psychological mechanisms. Workman and Reader (2004) assert there is an adequate room for evolutionary psychology to be erroneous with regard to psychological mechanisms that make up the human mind and be erroneous with respect to the evolutionary history of a particular psychological mechanism correctly identified by evolutionary psychologists. According to Ryle (2005), it is likely that the criticisms of adaptationism in evolutionary psychology may be closer to the truth when compared with evolutionary psychology; however, the closeness to the truth cannot be based on the reasons cited by these critics such as Gould. It is evident that there are relatively fewer psychological adaptations than the claim made by evolutionary psychologists, and that many of the adaptations advocated for evolutionary psychologists are derivatives or by-products of psychological adaptations; however, if evolutionary psychology is deemed to be wrong in this way, Workman and Reader (2004) assert that this faults in evolutionary psychology cannot be attributed to the search for psychological adaptations, but as a result of evolutionary psychology failing to correctly recognize these psychological adaptations. As Ryle (2005) maintains, critics of adaptationism in evolutionary psychology tend to mischaracterize the field of evolutionary psychology.

In conclusion, it is evident from the above discussion that the criticism of adaptationism evolutionary psychology can be overcome and that the success of its research program is imminent. There is no doubt that principles of evolutionary psychology are similar to the evolutionary biological perspectives. This simply means that if one accepts that the natural selection is the only framework that can be used to explain a function in biology, then, one is embracing the concept of evolutionary psychology. Recognizing that the evolution of the brain took place through the natural selection is the first step towards understanding what aspects of human mental properties can be linked to the natural selection. In addition, the empirical research in evolutionary psychology is designed with the main aim of identifying the adaptive and non-adaptive psychological traits. Perhaps, at the moment, evolutionary psychologists have not correctly identified one, but they will in future.

References

Buss, D. (1999). Evolutionary Psychology: The New Science of the Mind. Boston: Allyn and Bacon.

Gould, S. J., & Lewontin, R. C. (1979). The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme. Proceedings of the Royal Society of London , 581-598.

Rose, H., & Rose, S. (2000). Alas, Poor Darwin: Arguments against Evolutionary Psychology. New York: Harmony Books.

Ryle, A. (2005). The relevance of evolutionary psychology for psychotherapy. British Journal of Psychotherapy , 21 (3), 375–88.

Wilson, D. S., Dietrich, E., & Clark, A. B. (2003). On the inappropriate use of the naturalistic fallacy in evolutionary psychology. Biology and Philosophy , 18 (5), B669–681.

Workman, L., & Reader, W. (2004). Evolutionary psychology: An introduction. Cambridge : Cambridge University Press.