Leda Cosmides on “The newly emerging field of Evolutionary Psychology”
Evolutionary psychology weaves together cognitive science, human evolution, hunter gatherer studies, neuroscience, psychology and evolutionary biology, in an attempt to understand and map the human mind and brain. According to this new view, by understanding the adaptive problems our hunter-gatherer ancestors faced during their evolution, researchers can uncover the detailed functional designs of the emotions, reasoning mechanisms, and motivations that human evolution produced. My empirical work spans many areas – cooperation, coalitional (“us versus them”) psychology, statistical reasoning, visual attention, incest avoidance, threat interpretation, multiple memory systems, friendship, predator-prey reasoning – because one goal has been to illustrate just how useful an evolutionary approach can be. In all cases, however, we start with an adaptive problem our hunter-gatherer ancestors faced, and then try to figure out what a program well-designed for solving that problem might look like. From this task analysis, we derive empirical predictions – which we then test – about the design of the programs that solve this problem. This method has allowed us to discover mental mechanisms that no one had thought to look for before. For example, theories about the evolution of reciprocation led us to look for, and find, evolved programs designed for reasoning about social exchange, including procedures specialized for detecting cheaters. This result has recently been supported by cross-cultural experiments with hunter-horticulturalists at our study site in the Ecuadorian Amazon, and by neuropsychological work showing that cheater detection dissociates from other closely related forms of reasoning.