Chimpanzees are not conformists

Apes do not bow to the pressure of the majority - unless they benefit

Have their own head: chimpanzees © MPI for Psycholinguistics
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Those who want to belong to it often agree with the majority - in behavior and also in opinion. Not so our closest relatives: if it does not bring tangible benefits, chimpanzees do not adapt to the majority behavior. However, if a change of strategy promises them more reward, the great apes will certainly prove to be flexible opportunists, as researchers report in the trade magazine "PloS ONE".

The pressure of the majority is a strong force. Who wants to belong to it, at the workplace, in a social group or ah in the family, often adapts to the more or less subliminal social pressure to adapt and adapts its behavior to that of the majority - be it in terms of clothing, nutrition or leisure behavior. People often act as conformists. But what about our closest relatives, the chimpanzees? Do they also fit the majority? Researchers at the Max Planck Institute for Psycholinguistics in Nijmegen and their colleagues at the Max Planck Institute for Evolutionary Anthropology in Leipzig have now investigated this.

Majority alone does not encourage customization

Researchers studied the behavior of 16 chimpanzees kept at the Primate Research Center in Leipzig and twelve semi-wild chimpanzees from the Chimfunshi Wildlife Orphanage Trust in Zambia. There the great apes live under almost natural conditions. For their study, the researchers trained a small minority of both groups to serve a variety of food donors, the majority learned to serve a second variety. In both devices, the monkeys each received a peanut when they put a ball in an opening.

The scientists now observed whether the minority changed their strategy and also over time used the food donors of the majority. But that was not the case in the Leipzig or Zambian groups. "Chimpanzees seem to prefer to stick to proven and accepted strategies rather than accepting the equally successful majority strategy, " explains study leader Edwin van Leeuwen of the Max Planck Institute for Psycholinguistics in Nijmegen. Accordingly, the great apes are not conformists in this regard.

Which strategy brings more profit? MPI for Psycholinguistics

Strategy change for more profit

In a second experiment, the researchers tested whether the behavior of chimpanzees changed, if now both strategies - in this case both feed donors - were equally successful. Instead, they manipulated the minority's food donors so that instead of just one, they now released five peanuts for each ball. And that had consequences: more and more chimpanzees of the majority group realized that the machine of the minority was more profitable and now lined up with this. After some time, all but one had changed their strategy and joined the former minority. display

"Chimpanzees do not change their behavior under majority influence, but they are very accommodating if they can maximize their profits, " says Van Leeuwen. The incentive to give up the habitual behavior seems to be strong enough if it gives them more reward. "Peanuts are more important to them than popularity, " jokes the researcher. In other words, chimpanzees are not conformists, but when the opportunity is right, they act like opportunists.

The biologists emphasize, however, that it is not yet known how strongly these test results can be transferred to the behavior of wild chimpanzees. For there, under certain circumstances, the pressure could force a stronger conformity. "Female chimpanzees, for example, join other groups in the field, so they need to be integrated into the new group as well as possible, " says Van Leeuwen. "Conformity in adapting to the respective foraging strategies can help them achieve this integration." (PloS ONE, 2013; doi: 10.1371 / journal.pone.0080945)

(Max Planck Society, 16.12.2013 - NPO)