Humans have long been thought to be the most altruistic of species, but new studies suggest bonobos are every bit as keen on helping strangers. Researchers studying these apes in the wilds of Congo have uncovered the extent to which bonobos will go in exhibiting unrewarded kindness to others.
One experiment involved helping a stranger get food:
Sixteen bonobos were led one at a time into one of two adjacent rooms separated by a fence. The researchers hung a piece of apple from a rope just above the empty room, visible but out of reach. The apes couldn’t access the fruit or the rope. But if they climbed the fence they could reach a wooden pin holding the rope to the ceiling and release the dangling fruit, causing it to drop within reach of any bonobo that entered the next room.
Researchers found the bonobos were about four times more likely to release the food when a stranger was in the room than when the room was empty.
What’s more, the bonobos didn’t wait to be asked for help, they just offered it.... The bonobos helped just as often whether the stranger gestured for help or not.
Another experiment involved the concept of "emotional contagion", a basic form of empathy whereby one person's mood provokes a similar emotional response in those around them.
In another experiment, they had 21 bonobos watch a series of short videos. In some videos, the apes saw a familiar group member either yawning or making a neutral expression. In other videos they watched complete strangers from the Columbus Zoo in the U.S. behaving the same way.... The researchers found that stranger yawns were just as contagious as those of groupmates.
Jingzhi Tan, a postdoctoral scholar at the University California, San Diego and coauthor of the studies, said for species where there is an overwhelming benefit to bonding with outsiders, it is likely that such altruistic tendencies will form.
“All relationships start between two strangers,” Tan said. “You meet a stranger, but you may meet them again, and this individual could become your future friend or ally. You want to be nice to someone who’s going to be important for you.”