14 DAY TRIAL // Researchers have been trying to figure out why chimpanzees and bonobos behave so differently from each other for many years. In a recent study, investigators looked at the anatomical differences that exist between the brains of the two related primate species.
Though they resemble each other a lot, the two brains also have some marked differences. Experts believe that some of them may help explain why aggression is more typical to chimps than bonobos.
This may also help explain the incidence of tolerant behavior among bonobos, which chimps don't appear to be too capable of engaging in. This study is made all the more interesting by the fact that both species belong to the same genus.
Details of the new investigation appear in the latest issue of the esteemed scientific Journal of Social Cognitive and Affective Neuroscience, Science Blog reports. The team behind the work says that this is the most complete analysis on this issue ever put together.
“What’s remarkable is that the data appears to match what we know about the human brain and behavior,” explains the leader of the new analysis, James Rilling. The expert holds an appointment as an anthropologist at the Emory University.
“The neural circuitry that mediates anxiety, empathy and the inhibition of aggression in humans is better developed in bonobos than in chimpanzees,” the scientist goes on to say.
“By contributing to our basic understanding of how brain anatomy relates to social behavior, this study may provide clues to the brain dysfunction underlying human social behavioral disorders like psychopathy and autism,” Rilling explains.
Historically, the last common ancestor between bonobos and chimps on one hand, and humans on the other, lived some 6 million years ago. But the two primate species diverged from each other between 1 and 2 million years ago, which is recent in evolutionary terms.
This is why the differences in behavior they exhibit are so interesting. If 2 million years tops sufficed to make these changes, who knows how the two species will look like in another 2 million years? The study also puts the evolution of modern humans in a new perspective.
Chimpanzees tend to resolve conflict by using aggression, while bonobos are more likely to use behavioral mechanisms like [intercourse] and play to diffuse tension,” Rilling goes on to say.
“The social behaviors of the two species mirror individual differences within the human population,” the expert concludes.