Modules, Brain Parts, and Evolutionary Psychology

Abstract

The central focus in debates over broad evolutionary psychology is whether mental abilities can be understood as adaptive functions (Davies, 1996, p. 446). Narrow evolutionary psychology1 further closely couples the claim that mental abilities are adaptive to a commitment to modularity of mental functions. This linkage is presented as quite direct— if the mind is comprised of discrete modules, then we can ask what are the selective factors that promoted each module. If, on the other hand, the mind is comprised of a single, fully integrated, general processor, then it would be much harder for natural selection to promote cognitive capacities individually2. And it would be much harder for us to give an explanation of the evolution of particular mental abilities. Cummins and Allen (1998, p. 3) provide a succinct account of the link between modularity and narrow evolutionary psychology: Taking an evolutionary approach to the explanation of cognitive function follows naturally from the growing body of neuroscientific evidence showing that the mind is divisible. The picture that is emerging from both noninvasive studies of normal brain function and from clinically defined syndromes resulting from brain damage from strokes, injury, and neurodevelopmental disorders is one of different substrates subserving different cognitive functions... The Cartesian view of a seamless whole makes it hard to see how such a whole could have come into being, except perhaps by an act of divine creation. By recognizing the modularity of mind, however, it is possible to see how human mentality might be explained by the gradual accretion of numerous special function pieces of mind.