AWA: Academic Writing at Auckland

Evolutionary Psychology is an adaptationist approach to understanding human behaviour. The paradigm focuses on how specific adaptations of the mind evolved to meet the problems faced by our hunter-gatherer ancestors (Buller, 2005). This approach is attractive because it is capable of explaining the origin of all kinds of human behaviour, even maladaptive behaviour, provided that it was adaptive at the time when it evolved (Bolhuis, Brown, Richardson, & Laland, 2011). However Buller (2006) claims that “Evolutionary Psychology is wrong in almost every detail. The problem isn’t that it rests on 'one big mistake,' but that it makes little mistakes nearly every theoretical and empirical turn” (p. 481). This essay will argue that there are indeed numerous problems with both the theory itself and the empirical evidence used to support that theory, however certain changes to Evolutionary Psychology’s approach could result in a much better theoretical basis. The first of the problems lie with the five major tenets of Evolutionary Psychology, each of which is undermined either by evidence supporting a contradictory theory, or in the case of universalism, contradiction within the theory itself. The empirical evidence said to support Evolutionary Psychology discussed in this essay are a study using the Wason card selection task and a study on instances of child abuse in homes with either a step-parent or two biological parents, which have been used to support the idea of massive modularity, and a study on the mate preferences of men and women, which has been used in support of universalism.

The five major tenets of Evolutionary Psychology are the environment of evolutionary adaptedness (EEA), massive modularity, gradualism, universalism, (Bolhuis et al., 2011), and evoked culture (Barkow, Cosmides, & Tooby, 1995). The EEA refers to a stable ancestral environment, more specifically an African Pleistocene savannah, in which human psychological mechanisms evolved. An issue with this notion is that this landscape was not in fact stable, and varied across place, time, and lifestyle, meaning that the selection pressures that were present varied so widely that it becomes very difficult to determine what kind of selection pressures the adaptations of the human mind resulted from (Bolhuis et al.,). 

Massive modularity is the view that the mind consists of domain-specific modules, each tailored to compute a specific adaptational problem. These modules are said to be informationally encapsulated and opaque to consciousness. Evolutionary Psychology argues that a modular mind will outcompete domain-general mechanisms. However the structure of the human brain and data from animal experiments are more consistent with the idea of a flexible, domain-general mind than with a massively modular, domain-specific mind (Bolhuis et al., 2011).

Gradualism is the suggestion that, because our minds are made up of mechanisms adapted to be suitable for the EEA and our minds cannot adapt quickly and so have changed very little since then, there is an adaptive lag in the evolution of the human mind. It was argued that this resulted in a mismatch between modern life and the adaptations that were appropriate for the EEA. However genetic evidence shows that there has been significant change to human genes in the last 50,000 years as a result of changes made to the environment by humans, which brought about their own selection pressures (Bolhuis et al., 2011).

Universalism, or psychic unity, is the claim that the human mind has evolved psychological mechanisms that produce a universal human nature. An issue with this claim is that the structure of the brain is too complex to be specified in detail by genes, rather it is largely determined by developmental processes (Bolhuis et al., 2011). Another issue with the idea of universalism is that it contradicts Evolutionary Psychology’s emphasis on the importance of natural selection in shaping the human mind because evolution requires heritable variation (R. D. Gray, personal communication, March 9, 2018). Another aspect of universalism is evoked culture, where culture is not seen as infinitely variable, rather it is seen as being underpinned by a universal genetic programme (Bolhuis et al., 2011). In contrast to this idea, there is evidence that culture can have a dramatic effect on the selection pressures acting on humans, and thus genetic frequency. An example of this taking place is the spread of genes for lactose tolerance, which was brought about by the rise of dairy farming (Bolhuis et al., 2011).

A key study with findings in support of massive modularity, one of the tenets of Evolutionary Psychology, is one by Cosmides (1989) that used the Wason selection task to find evidence supporting the hypothesis that the human mind uses specialised cognitive processes to reason about social exchange. The study used two variations of the card selection task, one in formal terms and one in social terms. The study found that participants were better at solving the task when it was framed in a social contract context, using a situation involving drinking ages, than when it was framed in a formal context, merely using letters and numbers (Cosmides, 1989). The reason for this was said to be that a cheater detection device exists in the mind, with the ability to easily identify a situation where a benefit has been taken without a requirement having been met, so this module would only be of assistance in the social context and not the formal context, resulting in more participants being able to solve the task in the social context (Sperber & Girotto, 2002). However the Wason selection task does not provide appropriate evidence for the claim of the existence of a cheater detection module. This is due to the fact that comprehension of the premises in the task is easier to do when given in words, so the study’s results are due to the problem being easier to represent in context, and not due to a cheater detection module (Sperber & Girotto, 2002). Another problem with these findings is that the question given in the drinking age context made it clear that the rule was unidirectional, so participants knew that they ought to look for violations of the drinking age rule. The question did not provide this much information when given in the formal context. This provides an alternative explanation for the study’s findings.

Another study said to be evidence supporting massive modularity was carried out by Daly and Wilson (1985) which investigated the maltreatment risk for children at the hands of either a step- parent or biological parent. The study found that children under the age of five living with a step- parent were 40 times more likely to experience child abuse than children living with two biological parents. The explanation given for this was that a parental love mechanism exists in order to inhibit violent reactions in conflict with a child, but that this inhibition only occurs in the biological parents, and not step-parents (Buller, 2005). For this reason, the study was used to support the idea of massive modularity, giving the parental love mechanism as an example of an adaptive module in the mind. One of the issues with the use this of study to support massive modularity is that the cases of maltreatment sampled in the study included not only victims of physical abuse, but also sexual abuse and unintentional neglect. Sexual abuse and unintentional neglect do not involve being in conflict with the child, and so these are not relevant to the claim that there is a parental love module in the mind inhibiting certain behaviours during conflict with a child (Buller, 2005). A study that only included physical abuse in the sample found that children under the age of five living with a step-parent were only 8 times more likely to experience child abuse than children living with two biological parents (Buller, 2005). Another problem with the Daley and Wilson (1985) study is that the results may be impacted by a reporting bias, as people are more likely to report violence by a step-parent than a biological parent (Buller, 2005). An alternative explanation for the results of the Daley and Wilson (1985) study is that the explanation for the increased risk of abuse at the hands of step-parents is not biological, but rather due to familiarity, which would affect the level of attachment to the child. So there are several reasons that the Daley and Wilson (1985) study cannot be used to support the claims of Evolutionary Psychology, as there is neither proof of the existence of a parental love module, or an explanation for how the selection pressures of the EEA would have caused such a module to arise.

A piece of evidence said to be in support of the universalism tenet is a study by Buss (1994) on human mating strategies, which looked at 10,047 participants across 37 countries. This study found that, across cultures, men placed more importance on attractiveness than women, men preferred younger women and women preferred older men, women placed more importance on high social status than men, and women had more desire for mates with good financial prospects than men (Buss, 1994). It was claimed that this commonality in mate preferences for each gender supported the theory of universalism, as it shows species typical differences in mate selection behaviour between males and females (Bolhuis et al., 2011). However Eagly and Wood (1999) found that these differing preferences in mate selection may be due to social structure, as the sex differences found by Buss (1994) were less pronounced in societies where there was more social equality, so these sex differences may not be as universal as was thought. The support for Evolutionary Psychology by this study is made even less compelling by the fact that, in the Buss (1994) study, no sex differences were found for attributes that participants rated as being of more importance, such as kindness and humour, than the attributes that showed sex differences. Another reason that these mate preferences are not as universal as was claimed is that it only accounts for heterosexual men and women.

As Buller (2006) suggests, Evolutionary Psychology is indeed full of little mistakes. There are problems with the five major tenets, and with some major pieces of empirical evidence. These include the Cosmides (1989) study using the Wason selection task to support the idea of a cheater detection module, the Daly and Wilson (1985) study that was used to support the idea of a parental love module, and the Buss (1994) study that used the uniformity of differences in mate selection preferences between men and women to support universalism. However Evolutionary Psychology may not be unsalvageable. In order to improve the paradigm, firstly development needs to be taken seriously. Evolutionary Psychology tends to operate on the assumption that where humans have a trait that could be explained in terms of adaptation, this must be the case. However this ignores the fact that certain traits may just be by-products of something else. Secondly, Evolutionary Psychology should adjust the idea that the mind is massively modular and full of domain-specific mechanisms, and instead focus on the possibility of a flexible, domain-general mind, all the while taking neuroscience and brain structure into account. Further, Evolutionary Psychology ought to test its theories across a broad range of cultures to show that they really are universal, and to understand how culture itself may create a set of selection pressures. With changes such as these, Evolutionary Psychology, despite its many issues, may have the potential to become a theory that could be taken seriously.

References

Barkow, J. H., Cosmides, L., & Tooby, J. (Eds.). (1995). The adapted mind: Evolutionary psychology and the generation of culture. Oxford University Press, USA.

Bolhuis, J. J., Brown, G. R., Richardson, R. C., & Laland, K. N. (2011). Darwin in mind: New opportunities for evolutionary psychology. PLoS biology, 9(7), e1001109.

Buller, D. J. (2005). Evolutionary psychology: the emperor's new paradigm. Trends in Cognitive Sciences, 9(6), 277-283.

Buller, D. J. (2006). Adapting minds: Evolutionary psychology and the persistent quest for human nature. MIT press.

Buss, D. M. (1994). The strategies of human mating. American Scientist, 82(3), 238-249. Cosmides, L. (1989). The logic of social exchange: Has natural selection shaped how humans reason? Studies with the Wason selection task. Cognition, 31(3), 187-276.

Daly, M., & Wilson, M. (1985). Child abuse and other risks of not living with both parents. Ethology and sociobiology, 6(4), 197-210. 

Eagly, A. H., & Wood, W. (1999). The origins of sex differences in human behavior: Evolved dispositions versus social roles. American psychologist, 54(6), 408.

Sperber, D., & Girotto, V. (2002). Use or misuse of the selection task? Rejoinder to Fiddick, Cosmides, and Tooby. Cognition, 85(3), 277-290.