A new study suggests that chimpanzees and human toddlers are inclined to follow majority rule.
The study, which was published online in the journal Current Biology and written by Daniel Haun et al of the Max Planck Institutes for Evolutionary Anthropology and Psycholinguistics, showed that chimpanzees and 2-year old toddlers were both more likely to repeat a peer group’s actions than a single peer’s actions. The research indicates that both chimpanzees and humans evolved to follow majority rule, in contrast with other some other primates like orangutans, which were also tested.
Researchers showed test groups a box with three colored holes. Placing a ball in one of the holes would dispense a treat. The subjects would then watch either a group of four peers or a single peer place the ball into one of the colored holes, at which point the subjects were allowed to place the ball themselves to earn a treat. Chimpanzee and human subjects who viewed the peer groups were more likely to place the ball in the same hole as their peers.
When a group of orangutans were tested with the same experiment, they were more likely to pick a random hole than following their peer groups. This shows that orangutans do not have a developed detection of or inclination towards social majority.
Although prior research has suggested that humans are subject to majority rule, the study, titled “Majority-biased transmission in chimpanzees and human children, but not orangutans,” indicates that an inclination towards majority rule is in place at a very young age. Previous studies have confirmed the effect of a majority opinion in preschool-aged children, but Haun’s team tested an especially young age group to determine whether the effect is learned.
Haun and his team believe that humans evolved to follow majority rule in order to make safe, productive and reliable decisions that would benefit early human groups equally. Haun’s research also shows that chimpanzees have the same inclination and that other primates may have evolved to detect and follow majority rule.