Chimps Keen to Solve Puzzles without Need for Food Rewards: Study

A new study finds that chimpanzees love playing with brainteasers, irrespective of whether they get a reward or not.

A team of researchers followed six chimpanzees of a family group - half-brothers Phil, Grant and Elvis, one male and two females - at the Zoological Society of London's Whipsnade Zoo. They set up a homemade puzzle for the chimps that involved moving red dice through a network of plumbing pipes until they fall into an exit chamber, reports LiveScience.

The chimps had to prod sticks into holes in the pipes so as to change the direction of the dice and make them fall into a container. Instead of using dice, the research team carried out the experiment using Brazilian nuts. Chimps that were successfully able to complete the puzzle were given the reward of eating the nuts. The task is similar to how chimps use sticks inside a termite mound to pull the insects out of their nests and have them as a snack.

The research team found that the chimps were more interested in completing the puzzle just like human crossword addicts, regardless of whether they got a reward or not.

As part of an enrichment program, the chimps were also offered treats in separate boxes, which was independent of the chimps solving the puzzle. The chimps had complete freedom to decide whether to solve the puzzle or not as they would get a reward in either case.

"We noticed that the chimps were keen to complete the puzzle regardless of whether or not they received a food reward," study researcher Fay Clark, of the Zoological Society of London, said in a statement. "This strongly suggests they get similar feelings of satisfaction to humans who often complete brain games for a feel-good reward."

The findings of the study are published in the American Journal of Primatology.