Pointing, withholding information, and deception in capuchin monkeys (Cebus apella).

Brown capuchin monkeys, like 4-year-old children and human-socialized chimpanzees, showed communicative and deceptive pointing in experiments in which they benefited by indicating, accurately or falsely, the location of hidden food. All 3 capuchin monkeys tested (13, 19, and 26 years old) pointed communicatively in the presence of a cooperative trainer. One human-reared monkey pointed without any training and frequently gazed at her human respondent; as with apes, extensive exposure to humans may promote some human-like responses in monkeys. Another capuchin withheld pointing when beneficial, whereas the 3rd learned to obtain the hidden food by pointing deceptively in the presence of a competitive trainer. Such deceptive pointing by one monkey and withholding of information by another suggest that primates' deceptive pointing in an experimental situation is explainable in terms of response inhibition and conditional discrimination learning.