Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regards to the ancestral problems they evolved to solve. In this framework, psychological traits and mechanisms are either functional products of natural and sexual selection or non-adaptive by-products of other adaptive traits.
Adaptationist thinking about physiological mechanisms, such as the heart, lungs, and the liver, is common in evolutionary biology. Evolutionary psychologists apply the same thinking in psychology, arguing that just as the heart evolved to pump blood, and the liver evolved to detoxify poisons, there is modularity of mind in that different psychological mechanisms evolved to solve different adaptive problems. These evolutionary psychologists argue that much of human behavior is the output of psychological adaptations that evolved to solve recurrent problems in human ancestral environments.
Some evolutionary psychologists argue that evolutionary theory can provide a foundational, metatheoretical framework that integrates the entire field of psychology in the same way evolutionary biology has for biology.
Evolutionary psychologists hold that behaviors or traits that occur universally in all cultures are good candidates for evolutionary adaptations, including the abilities to infer others' emotions, discern kin from non-kin, identify and prefer healthier mates, and cooperate with others. Findings have been made regarding human social behaviour related to infanticide, intelligence, marriage patterns, promiscuity, perception of beauty, bride price, and parental investment. The theories and findings of evolutionary psychology have applications in many fields, including economics, environment, health, law, management, psychiatry, politics, and literature.