Brutal behavior can be an effective pathway to power. And not only in humans, but also in primates, as shown by a study published April 24 in the journal PeerJ Life and Environment.
According to the study, male monkeys with short-tempered, greedy and overbearing personalities achieve higher positions on the social ladder and are more successful in having offspring than their more deferential and conscientious peers. However, scientists wonder why not all chimpanzees have aggressive behavior if it appears to be advantageous. To answer this question, researchers at the University of Edinburgh and Duke University followed 28 male chimpanzees for a time in Gombe National Park, Tanzania.
In a previous study, the same scientists had shown that some chimpanzees are more sociable while others prefer solitude. In addition, some are more relaxed while others are more combative. In this new study, researchers found that male monkeys with certain personality traits — in this case, a combination of high dominance and low conscientiousness — are more successful in life than others. “Personality matters,” says Joseph Feldblum, associate professor of evolutionary anthropology at Duke University and one of the study’s lead authors.
While it is not surprising to find that bullying has its advantages, for some researchers findings such as these present a conundrum: If males with certain personality tendencies are more likely to rise up and reproduce, and pass on the genes for those traits to their offspring, then why don’t all males exhibit those traits? According to a long-held theory, different personality traits can be advantageous at different times in animals’ lives. For example, although aggression may give an advantage to young male monkeys, it may be counterproductive when they become older.
