An argument is presented showing that the postulation of psychological capabilities that are jointly necessary to and specific to other capabilities involves strong theoretical commitments that have not generally been recognized. Examples are drawn from language development and evolution. (SS)

Reed believes the proper study of psychology is not mind or stimulus-response phenomena but ways animals (including humans) encounter the world. In this view, animals are seen in environmental and evolutionary contexts; a fundamental concept is not mind or behavior but affordance or what environments offer animals; and new topics, such as…