Abstract # 13105 Event # 140:

Scheduled for Friday, August 10, 2018 02:45 PM-03:00 PM: (Chula Vista ) Oral Presentation


CLEARLY NOT CONSERVATIVE: CHIMPANZEES AND GORILLAS SHOW FLEXIBLE LEARNING WITH A CAUSALLY-CLEAR TASK

L. M. Hopper and S. L. Jacobson
Lincoln Park Zoo, Lester E. Fisher Center for the Study and Conservation of Apes, Chicago, IL 60614, USA
line
     In contrast to wild ape behavior, captive apes often appear conservative when presented with problem-solving tasks. They seem limited in their ability to adopt new solutions in response to changing task demands. We argue that this conservatism may be due to apes’ lack of causal understanding of previously-employed tasks. To test this, we presented 13 zoo-housed apes (Pan troglodytes and Gorilla gorilla gorilla) with a puzzle in which they had to remove four of five straws to release a reward. The fifth straw was irrelevant to reward retrieval, allowing us to test the apes’ causal understanding. All apes successfully obtained the reward in their first trial and 11 used the efficient 4-straw strategy. Across multiple trials, the apes only removed relevant straws in 92.3% on average and four of the apes used the efficient strategy in every trial. To test their flexibility, a new task-configuration was then presented that required only two straws to be removed, although all five straws remained. Now, no ape used the 4-straw strategy that had previously been efficient and 12 switched to the efficient 2-straw strategy on their first trial. Across trials, the apes were 89.7% efficient, which was not significantly different when presented with the previous configuration (p>0.05). This provides evidence that when apes understand causality, they are flexible and efficient problem-solvers, calling into question previous claims of conservatism.