Carpe diem: adaptation and devaluing the future.

Organisms typically "discount the future" in their decision making, but the extent to which they do so varies across species, sexes, age classes, and circumstances. This variability has been studied by biologists, economists, psychologists, and criminologists. We argue that the conceptual framework required for an interdisciplinary synthesis of knowledge in this area is the evolutionary adaptationist analysis of reproductive effort scheduling pioneered by George Williams.