Solution by rhesus monkeys of multiple sign problems utilizing the oddity technique
Abstract"(1) Three rhesus monkeys were trained to solve problems involving response to four antagonistic variables. Solution of this problem was obtained using as stepwise training procedure involving 11 steps. (2) The subjects solved the problem within 2440 to 4480 trials. (3) In terms of Lashley's classification of higher order generalizations, this investigation can be considered as either a fourth order generalization, or a problem involving simultaneous solution of a second and third order generalization. (4) Three general factors operated to produce difficulty: (a) similarity of differential signs, (b) ambiguity of reinforcement, and (c) infrequency of differential reinforcement."