Monkeys can deduce what other monkeys and humans think, want and see based on visual cues, according to a new paper.
This inspired Jonathan Flombaum, a graduate student in the psychology department at Yale University and colleague Assistant Professor Laurie Santos to test the monkeys on their ability to assess the visual perspectives of others.
All involved a human holding a grape next to a curious monkey.
For the first experiment, the human grape holder stood either facing the monkey or turned away from it.
For the final experiment, the human held up a small rectangular cut-out that blocked either the human's eyes or his mouth.
Interacting with other monkeys Reading other monkeys' minds may help these primates to attract mates or protect offspring (Image: Laurie Santos) "We know that cells in the monkey superior temporal sulcus [part of the brain] encode this information.
"If we are right that rhesus monkeys can 'mind read' in the ways that we say they can, then our own similar abilities probably did not evolve in us," Flombaum says.
While Flombaum does not believe in true psychic phenomena, he thinks that humans experience intuition based on such deductions; for example, when a person gets a sudden feeling that a situation should be avoided, or when a bad vibe suggests that someone is lying or staring, even when the possible victim cannot be sure.
People with autism appear to have a hyperactive amygdala, part of the brain that deals with emotions and negative feelings.
Monkey traits This monkey research is also helping researchers to learn more about autism (Image: Laurie Santos) Dr Brian Hare, a researcher and postdoctoral associate at the Max Planck Institute for Evolutionary Anthropology, studies chimpanzees.