title: The comparative psychology of same-different judgments by humans (Homo sapiens) and monkeys (Macaca mulatta).
abstract: The authors compared the performance of humans and monkeys in a Same-Different task. They evaluated the hypothesis that for humans the Same-Different concept is qualitative, categorical, and rule-based, so that humans distinguish 0-disparity pairs (i.e., same) from pairs with any discernible disparity (i.e., different); whereas for monkeys the Same-Different concept is quantitative, continuous, and similarity-based, so that monkeys distinguish small-disparity pairs (i.e., similar) from pairs with a large disparity (i.e., dissimilar). The results supported the hypothesis. Monkeys, more than humans, showed a gradual transition from same to different categories and an inclusive criterion for responding Same. The results have implications for comparing Same-Different performances across species--different species may not always construe or perform even identical tasks in the same way. In particular, humans may especially apply qualitative, rule-based frameworks to cognitive tasks like Same-Different.
authors.affiliation: Department of Psychology, Park Hall, University at Buffalo, the State University of New York, Buffalo, NY, 14260, USA. psysmith@buffalo.edu
authors.forename: J David
authors.initials: JD
authors.lastname: Smith
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Redford
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Haas
authors.forename: Mariana V C
authors.initials: MV
authors.lastname: Coutinho
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Couchman
mesh_terms: D000818:Animals; D003071:Cognition; D003657:Decision Making; D015186:Hominidae; D006801:Humans; D007600:Judgment; D008253:Macaca mulatta; D011587:Psychology, Comparative / Q000379:methods*