Bonobos have demonstrated an impressive ability to understand others’ mental states, showcasing a fundamental capacity for cooperation. This capacity, known as theory of mind, allows individuals to recognize that others may hold different perspectives or beliefs. Researchers have long debated whether non-human great apes possess this essential skill, with some studies suggesting it may be more evolutionarily ancient than previously thought.
A recent study by Luke Townrow and Christopher Krupenye at Johns Hopkins University found evidence of theory of mind in bonobos. In a controlled experiment, the researchers tested three male bonobos’ ability to identify ignorance in someone they were trying to cooperate with and gesture towards them to help solve a task.
In the experiment, a barrier was placed between an experimenter and a set of upturned plastic cups containing treats. The experimenter could watch where the treat was placed under one of the cups in the “knowledge condition” but had their view blocked in the “ignorance condition.” The researchers observed whether the bonobos pointed at the cup after the barrier was removed over 24 trials for each condition.
The results showed that, on average, the bonobos took 1.5 seconds less time to point and successfully identified the location of the treat in approximately 20% more trials in the ignorance condition. This demonstrates that they can take action when realizing someone has a different perspective from their own.
While the study’s findings may not apply to all bonobos, they provide significant experimental support for existing research on wild apes. The results also suggest that a capacity for theory of mind exists within the biology of bonobos and likely their common ancestor as well. This understanding could have allowed our ancient human relatives to communicate and coordinate more effectively with their social partners, potentially bolstering cooperation and coordination in their social worlds.
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Source: https://www.newscientist.com/article/2466616-bonobos-can-tell-when-they-know-something-you-dont