Selective investment theory: Recasting the functional significance of close relationships

In this article we present an evolutionary theory of altruism-Selective Investment Theory (SIT). The essence of SIT is that human social bonds evolved as overarching, emotion regulating mechanisms designed to promote reliable, high-cost altruism among individuals who depend on one another for survival and reproduction (e.g., offspring, mates, coalition members). We view the social bond as a dynamic memory complex, with cognitive, affective, and neurohormonal features. When activated, this complex works to minimize self versus other motivational conflicts associated with altruistic decision making. Our proposal that social bonds evolved because they promoted giving away (as opposed to getting) valuable resources represents a departure from traditional wisdom, and has important implications for interpreting and investigating close relationship phenomena.