Reports

Conservation of Liquid and Solid Quantity by the Chimpanzee

Science  01 Dec 1978:
Vol. 202, Issue 4371, pp. 991-994
DOI: 10.1126/science.202.4371.991

Abstract

Sarah, an adult "language"-trained chimpanzee, made accurate same-different judgments on quantities of liquid and solid matter and conserved both types of quantity despite a transformation in an irrelevant property (shape). Control tests showed that she judged on the basis of inference rather than perceptual evaluation of the quantities. She failed to make accurate same-different judgments on the basis of number, and she was not tested for conservation of this type of quantity.