Chimpanzees are Rational, Not Conformist: Chimps Choose Logic Over Popularity

It turns out that chimpanzees are more rational than you might expect. Scientists have discovered that while chimps are sensitive to social influences, they maintain their own strategy to solve a problem rather than conforming to what the majority of group members are doing.

Chimpanzees are known for their curious and social nature. They're also known to be hesitant about abandoning their personal preferences, even when a familiar behavior becomes extremely ineffective. In order to find out under what circumstances chimpanzees would adjust their behaviors, the researchers conducted a series of experiments.

The researchers examined 16 captive chimps and 12 semi-wild chimps. These animals were trained on two different vending machines; a minority of the group was made familiar with one machine and the majority of the group members with the other machine. Wooden balls were placed in the chimps' enclosure and could be used in the machines to receive one peanut for each ball.

First, the researchers checked to see if the chimpanzees in the minority group would change their behavior toward using the vending machine being used by the majority of the group. It turned out that the chimps continued to use the same machine, regardless of social pressures. Then, the scientists changed the profitability of the vending machines; the one that the minority used became more profitable and spat out five peanuts for every ball inserted.

So what did the researchers find? Over time, the majority of chimpanzees gradually switched to using the most profitable machine. This indicated that the chimps relied on logic rather than on social influence.

"Where chimpanzees do not readily change their behavior under majority influences, they do change their behavior when they can maximize their payoffs," said Edwin Van Leeuwen, one of the researchers, in a news release. "We conclude that chimpanzees may prefer persevering in successful and familiar strategies over adopting the equally effective strategy of the majority, but that chimpanzees find sufficient incentive in changing their behavior when they can obtain higher rewards somewhere else."

The findings reveal a little bit more about how chimps better adapt to and survive in the wild. More specifically, it shows the strategies they use depend on logic rather than on popularity.

The findings are published in the journal PLOS One.