Bonobos are famous for their cooperative, peaceful way of life. The animals share food, are friendly towards strangers, and previous studies have even found that their brains may be hardwired for empathy. Now, a new study adds to that image of the peace-loving bonobo, showing that bonobos may be more interested in cooperation than assessing aggressive or threatening behavior, according to The Atlantic.

In the study, published in Proceedings of the National Academy of Sciences, researchers showed bonobos images of neutral or emotional bonobos. Some of the emotional images portrayed the apes engaged in “affiliative behaviors” like grooming, reports The Atlantic, while others showed them in threatening or aggressive poses. Researchers used a “dot-probe” test, in which a dot appeared on screen with each image, to discern which images the bonobos paid most attention to. By timing how long it took the animals to locate the dot in each photo, researchers were able to get a sense of which images were most interesting to them.

The study found that the apes paid the most attention to positive images, especially those which portrayed bond-forming activities. “The researchers ran the test over 25 sessions, 13 tests to a session,” The Atlantic explains. “[They] found that the bonobos located the dot most quickly when it appeared in the place of an emotional image—specifically, images depicting 'affiliative behaviors’ like grooming (a prized bonding ritual among bonobos), and ‘behaviors that are highly contagious,’ like yawning, which researchers believe indicates empathy."

Researchers believe these findings not only reinforce existing understandings of bonobos as cooperative and empathetic, but reveal that for the animals, recognizing pro-social behavior may be more important for survival than threat detection.

“In social animals, the fast detection of group members’ emotional expressions promotes swift and adequate responses, which is crucial for the maintenance of social bonds and ultimately for group survival,” the study explains. “The results suggest that protective and affiliative behaviors are pivotal in bonobo society and therefore attract immediate attention in this species.”

[h/t The Atlantic]