Zina B. Ward

Contemporary psychologists and neuroscientists often ignore or minimize individual differences because variation between subjects can be an obstacle to scientific inference and explanation. This dissertation examines the tools available, and considers the tools needed, to deal appropriately with individual differences in cognitive science. It proposes a philosophical account of what it takes to explain mental and neural variation and suggests that several scientific methods must be modified in light of such variation. Methods discussed include rational analysis, hierarchical Bayesian models, and brain registration procedures. The project also examines the ethics of research on individual differences, which is especially pressing given how prejudice has historically shaped inquiry into human variation.