The executive functions and self-regulation: an evolutionary neuropsychological perspective.

Neuropsychology has customarily taken a molecular and myopic view of executive functioning, concentrating largely on those proximal processes of which it may be comprised. Although commendable as a starting point, such an approach can never answer the question, "Why executive functioning?" The present paper encourages neuropsychologists to contemplate the longer-term, functional nature of the executive functions (EFs), using an evolutionary perspective. For purely illustrative purposes, a previously developed model of the EFs is briefly presented and is then examined from an evolutionary perspective. That model views the EFs as forms of behavior-to-the-self that evolved from overt (public) to covert (private) responses as a means of self-regulation. That was necessary given the interpersonal competition that arises within this group-living species. The EFs serve to shift the control of behavior from the immediate context, social others, and the temporal now to self-regulation by internal representations regarding the hypothetical social future. The EFs seem to meet the requirements of a biological adaptation, being an improbable complex design for a purpose that exists universally in humans. Discovering the adaptive problems that the EFs evolved to solve offers an invaluable research agenda for neuropsychology lest that agenda be resolved first by other scientific disciplines. Some adaptive problems that the EFs may have evolved to solve are then considered, among them being social exchange (reciprocal altruism or selfish cooperation), imitation and vicarious learning as types of experiential theft, mimetic skill (private behavioral rehearsal) and gestural communication, and social self-defense against such theft and interpersonal manipulation. Although clearly speculative at the moment, these proposals demonstrate the merit of considering the larger adaptive problems that the EFs evolved to solve. Taking the evolutionary stance toward the EFs would achieve not only greater insight into their nature, but also into their assessment and into those larger adaptive capacities that may be diminished through injury or developmental impairment toward that system.