The past explains the present

TLDR

Organisms’ adaptive behavior is shaped by past selection pressures, with adaptations reflecting ancestral environments and emotional categorization mapping new situations onto evolutionarily recurrent classes, so the present is experienced only as a version of the past. The authors argue that adaptive behavior arises from underlying adaptations shaped by past selection and from present conditions resembling past conditions in functionally important ways; even planning mechanisms rely on ancestrally shaped categorization, and the statistical structure of iterated events is encoded in the algorithms governing emotional states.

Abstract

Present conditions and selection pressures are irrelevant to the present design of organisms and do not explain how or why organisms behave adaptively, when they do. To whatever non-chance extent organisms are behaving adaptively, it is 1) because of the operation of underlying adaptations whose present design is the product of selection in the past, and 2) because present conditions resemble past conditions in those specific ways made developmentally and functionally important by the design of those adaptations. All adaptations evolved in response to the repeating elements of past environments, and their structure reflects in detail the recurrent structure of ancestral environments. Even planning mechanisms (such as "consciousness"), which supposedly deal with novel situations, depend on ancestrally shaped categorization processes and are therefore not free of the fast. In fact, the categorization of each new situation into evolutionarily repeating classes involves another kind of adaptation, the emotions, which match specialized modes of organismic operation to evolutionarily recurrent situations. The detailed statistical structure of these iterated systems of events is reflected in the detailed structure of the algorithms that govern emotional state. For this reason, the system of psychological adaptations that comprises each individual meets the present only as a version of the past.