Delay of gratification in chimpanzees (Pan troglodytes)

✍ Scribed by Michael J. Beran; E. Sue Savage-Rumbaugh; James L. Pate; Duane M. Rumbaugh

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 97 KB
• Volume: 34
• Category: Article
• ISSN: 0012-1630
• DOI: 10.1002/(sici)1098-2302(199903)34:2<119::aid-dev5>3.0.co;2-p

✦ Synopsis

Delay of gratification in 3 chimpanzees (Pan troglodytes) was examined by using a paradigm based on research with children. The chimpanzees either pressed a door-bell button during a trial and received one reward (the immediate reward) or did not press the doorbell and received another reward (the delayed reward). Two chimpanzees were language-trained, and a 3rd was non-language-trained. Foods (one more-preferred and one less-preferred), photographs of those foods, or lexigrams representing those foods were presented to the chimpanzees. All 3 chimpanzees delayed gratification when foods were physically present. One language-trained chimpanzee also delayed gratification with lexigrams present, and the 2nd language-trained chimpanzee delayed gratification in all three conditions. Language competence and early rearing are proposed as explanations for the different performances of these chimpanzees.