Catherine Driscoll

Sarah Hrdy argues that women (1) possess a reproductive behavioral strategy including infanticide, (2) that this strategy is an adaptation and (3) arose as a response to stresses mothers faced with the agrarian revolution. I argue that while psychopathological and cultural evolutionary accounts for Hrdy's data fail, her suggested psychological architecture for the strategy suggests that the behavior she describes is really only the consequence of the operation of practical reasoning mechanism(s) – and consequently there is no reproductive strategy including infanticide as such, nor could the alleged strategy be sufficiently mosaic to count as an adaptation. What might count as an adaptation is a ‘window’ before bonding that permits practical reasoning about the reproductive value of infants and hence variable maternal investment, and which, contra (3) arose early in hominid history due to a combination of increases in infant dependency and increased human abilities for conditional practical reasoning.

David Buller and Valerie Hardcastle have argued that various discoveries about the genetics and nature of brain development show that most?central? psychological mechanisms cannot be adaptations because the nature of the contribution from the environment on which they are based shows they are not heritable. Some philosophers and scientists have argued that a strong role for the environment is compatible with high heritability as long as the environment is highly stable down lineages. In this paper I support this view by arguing that the discoveries Buller and Hardcastle refer to either do not show as strong a role for the environment as they suggest, or these discoveries show that the brain's developmental process depends in many cases on input from the environment that is highly stable across generations.