The ritual behaviours which are associated with obsessive-compulsive disorder (OCD) could be considered to be an extension of the mechanisms that drive more adaptive behaviour. Marks and Nesse (1994) proposed examples of this such as a concern for others, hoarding and grooming behaviour; if the needs of other members of a group are ignored, the likelihood of ostracism from the group increases, individuals with OCD may often be overly concerned with the fear of harming others; hoarding in animals guards against future shortages and protects the individual from periods in which the resource may be scarce, this may be excessively exaggerated in some obsessive-compulsive individuals; parasitism in animals is reduced by grooming and in some species this promotes social interaction, extreme grooming e.g. hand washing is a common symptom of many OCD sufferers.
Prepotency is an adaptive function whereby we have an inborn predisposition to respond more reactively to stimuli that would have been a threat to us in the EEA. If we were to experience anxiety after a loss, this would not have been adaptive therefore we developed a response to potential threats, ancestors who were able to respond to threats efficiently were therefore more likely to survive and pass on their genes to subsequent generations. Henceforth, as a result of natural selection, our nervous system has been shaped to attend more to certain cues than to others. An example for this can be found in a study by Bennett-Levy & Marteau (1969) in which it was found that participants expressed the greatest fear of animals who bore the least resemblance to the human form in terms of skin texture and number of limbs.
Preparedness adds a notion of flexibility to our responses in that we develop selectiveness as to what stimuli to respond to through experience of our environment. Seligman proposed that animals, including humans, are biologically prepared to rapidly learn an association between particular stimuli and fear (for example, those which may be life threatening) and that once this association has been learned, it is difficult to get rid of.
A strength of this approach is the extent to which the adaptive functions of anxiety disorders have been supported by research. The research outlined in the first half of this essay offers explanations as to why this behaviour has persisted throughout our development. This is valuable as it lifts the approach beyond non-falsifiable conjecture via the generation and acceptance of testable hypotheses.
However, other theorists have argued that the approach is too speculative. This is due to the post-hoc nature of the explanation’s emphasis on the role of the EEA. This can be seen as a weakness as there is very little conclusive evidence to support the social nature of the EEA.
Another problem for the evolutionary approach is its’ over emphasis on the role of the EEA. Theorists have criticised the ‘Flintstones View’ of humanity by viewing everything in Stone Age terms. This is problematic as it neglects the possibility that other environments and historical periods may have had an influence on the development of anxiety disorders.
Evolutionary Psychology has also been criticised for being too deterministic in its outlook. The importance of anxiety disorders being influenced by our genes adapting to pressures in our environment is a problem as it does not consider the role of free will. It can also be seen as reductionist as the emphasis on genes neglects the consideration of other means of transmitting behaviours between generations, e.g. culture.
A final criticism of these explanations lies in their Panglossian nature. Evolutionary psychologists assume that there is an adaptive function for every behaviour that has persisted, including anxiety disorders. It could be that this has persisted because it is neutral or that the genes related to it are also connected with another behaviour that is adaptive.
Despite these problems, the theories of anxiety disorders are based upon the process of evolution which is fact, therefore evolution must play some role, but perhaps within a multi-factoral, eclectic approach.
