Evolutionary psychiatry. Adaptationist and nonadaptationist conceptualizations

Abstract

Darwin's theory of evolution, and in particular one of its mechanisms, natural selection, is being used as the explanatory cornerstone of many unsolved problems in human biology and human affairs. Psychiatry is an example of that. Darwinian psychiatry's main proponents endorse the adaptationist program to carry out their project to implement an evolutionary psychiatry. The adaptationist program is an attempt to view all evolutionary novelties as adaptations, i.e., classically, features that favour survival and/or reproduction. This position is definitely teleological, and anthropomorphism plays a central role in its construction. This paper takes issue with the adaptationist approach. We argue that organism–environment interactions are bidirectional processes. Hence, as a result of the fact that “a surprisingly large amount of the environment, which affects natural selection on an animal is the more or less direct result of the animals own behavior” [Waddington, C.H., 1976. Evolution of the subhuman world. In: Jantsch, E., Waddington, C.H. (Eds.), Evolution of Consciousness. London, UK, pp. 11–23], a more appropriate term to describe these interactions appears to be construction rather than adaptation alone [Lewontin, R., 2000. The triple helix: gene organism and environment. Harvard Univ. Press]. We present factual anatomical, physiological and clinical data critical of the platonic Kraepelinean classification of mental diseases, and claim that this classification is contrary to modern ideas on the evolution of nervous systems. We argue against the view of mainstream evolutionary psychiatrists that mental diseases are adaptations. We do so on two accounts. One is methodological; authors in this position do not ask whether every disease has evolutionary causes, but assume this in order to explain all diseases in such terms. The other mistake is biological; it is their belief that adaptation is the driving force of evolution while in fact it is just an outcome of evolution. The current status of the controversy between cognitive versus emotional experiences as essentially independent is reviewed, and evidence is presented, that they cannot be considered platonic, categorically independent functions of CNSs. These data, taken together, plus arguments derived from the high degree of plasticity of nervous systems, lead us to suggest a different approach to classification of mental diseases.