Helping strangers was long thought to be unique to humans, but new research on bonobos suggests our species is not as exceptional in this regard as we like to think. The study published in the journal Scientific Reports suggests that bonobos, like humans, may simply be eager to make a good first impression. Bonobos, a species of apes, will go out of their way to help strangers too, said Jingzhi Tan from Duke University in Durham, North Carolina. The researchers studied wild-born bonobos at the Lola ya Bonobo sanctuary in the Democratic Republic of Congo.

In one experiment, they found that bonobos will help a stranger get food even when there is no immediate payback. A total of 16 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 could not 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.

The bonobos released the fruit roughly four times more often when an unfamiliar bonobo was in the adjacent room than when the room was empty. What is more, the bonobos did not wait to be asked for help, they just offered it. The researchers changed the size of the mesh surrounding the stranger’s room so that in some trials they were able to stick their arms through the openings in the screen to beg for the treat, and in other trials, they were not. The bonobos helped just as often whether the stranger gestured for help or not, the study showed.