Bonobos can recognize when others lack knowledge and adjust their communication accordingly, a new study published in PNAS suggests.

In a study by Johns Hopkins University researchers, male bonobos were sat opposite a human partner one by one. A second person would place a treat – usually a Cheerio – under one of three cups. The bonobo would always be able to see where the treat was, but the human partner was sometimes kept in the dark.

The bonobo would only be able to have the treat if the human could find it.

When the bonobo knew the human didn’t know, he would “quite demonstratively” point to the right cup. This behavior indicates that bonobos may possess a basic understanding of others’ ignorance and use it to guide cooperative interactions.

These findings challenge long-standing beliefs that non-human primates cannot communicate based on mental state attributions and suggest that bonobos at least have a more flexible and advanced social cognition than previously thought.