According to a recent study published in Proceedings of the Royal Society B, a team of psychologists from Hebrew University of Jerusalem, the University of York, and Duke University have discovered that great apes can engage in reciprocal food exchange under certain conditions. While previous research has shown that humans tend to share food and other resources with those who have shared with them in the past, the same behavior is rare in other animals, as it is typically viewed as a competitive act.
To determine whether great apes could engage in reciprocal food sharing, the researchers conducted experiments with captive chimpanzees and bonobos. In the initial experiment, the apes were placed in adjacent cages with a plate of treats that could be shared through an opening between the cages. However, few apes chose to share their treats in this scenario. When the researchers changed the conditions so that the first ape could only obtain their treat by sharing with the second ape and then repeating the exercise with roles swapped, the apes shared approximately 70% of the time.
The researchers replicated the experiment with four-year-old children and observed similar results, leading them to conclude that apes are capable of reciprocal food exchange under certain circumstances. They suggest that early humans may have had to overcome their aggressive tendencies towards food sharing in order to establish stronger social ties.