How Useful Are the Concepts “Innate” and “Adaptation” for Explaining Human Development

Abstract

Adaptationist thinking has played an important role in the life sciences, especially since the neo-Darwinian modern synthesis of Darwinian natural selection and Mendelian genetics that occurred in the 1930s. Adaptationist approaches focus on what a phenotype ‘‘is for’’ by reasoning about what particular adaptive problem it might have solved in an ancestral environment. This in turn leads to hypotheses regarding the manner in which the phenotype in question may have enhanced reproductive success. In the past 20 years or so, largely through the work of evolutionary psychologists, adaptationist explanation has become more common in psychology. During this same period of time, core knowledge explanations of human development have also increased in popularity. Such researchers conceive of the core capacities for which they marshal empirical evidence as the products of natural selection and, therefore, adaptations. In this article, I briefly describe these two approaches to human development and place their adaptationist programs in a historical context. I then describe recent developments that complicate adaptationist and innatist claims and briefly discuss the possibility of an alternative evolutionary meta-theory. In a general sense, evolutionary psychology can be understood as the study of the effect of evolutionary change on psychological development. It is sometimes capitalized as Evolutionary Psychology to single out the so-called Santa Barbara school of evolutionary psychology associated primarily with the theorizing of Tooby and Cosmides, but also Pinker, Buss and a few others [e.g., Buss, 1995; Pinker, 2003; Tooby & Cosmides, 1992]. Although my goal in this necessarily brief article is to discuss adaptationism more generally, I focus on evolutionary psychology because it lays out the basic assumptions that are in play when psychologists claim that a given phenotype is the result of an adaptation and is, accordingly, in some sense innate. In broad strokes, evolutionary psychology explains currently adaptive behavior – and sometimes maladaptive behavior through relying on mismatch arguments between our ancestral and modern environment – in terms of specific cognitive adaptations that are the product of the differential reproductive successes of our hominid ancestors. It is explicitly adaptationist because it explains human development by attempting to