Adolescent humans and chimps seek risky option
Just like humans, chimpanzees show rapid changes in hormone levels during adolescence, start forming new bonds with peers, show increases in aggression and compete for social status.
To find out if other aspects of their behaviour mirrored that of human teens, researchers played two games with 40 wild-born chimps at a sanctuary in the Republic of Congo.
In the first test, the chimps were asked to choose between a box which always contained peanuts, or take a chance on a box which might have either a cucumber slice or a banana slice inside.
The chimpanzees could play it safe and choose the peanuts, or gamble on winning a delicious banana, at the risk of ending up with an unappetizing piece of cucumber.
During several rounds of the test, adolescent chimpanzees were 55 per cent more likely than adults to take the risky option.
It suggests that just like human teens, adolescent chimpanzees will also seek out the riskier option if there is a greater reward on offer.
In the second test, the chimps’ “delayed gratification” skills were tested by allowing chimpanzees to receive one banana slice immediately or wait for one minute to receive three slices.
Risk-taking behaviour ‘deeply biologically ingrained’
Human teens tend to be more impulsive than adults so they would be more likely to take the immediate reward.
Although the young chimps delayed their reward about the same amount as adults, they threw more tantrums during the one-minute delay than adult chimpanzees.
It suggests that, unlike humans, adolescent chimps are no more impulsive than adults, but they deal with losing as badly as human teens.
“Prior research indicates that chimpanzees are quite patient compared with other animals, and our study shows that their ability to delay gratification is already mature at a fairly young age, unlike in humans,” Rosati said.
“Risk-taking behaviour in both adolescent chimpanzees and humans appears to be deeply biologically ingrained, but increases in impulsive behaviour may be specific to human teens.”
The research was published online in the Journal of Experimental Psychology: General.