One of the things that defines humans most is our ability to read others’ minds — that is, to make inferences about what others are thinking. To build or maintain relationships, we offer gifts and services — not arbitrarily, but with the recipient’s desires in mind. When we communicate, we do our best to take into account what our partners already know and to provide information we know will be new and comprehensible. And sometimes we deceive others by making them believe something that is not true, or we help them by correcting such false beliefs.
All these very human behaviors rely on an ability psychologists call theory of mind: We are able to think about others’ thoughts and emotions. We form ideas about what beliefs and feelings are held in the minds of others — and recognize that they can be different from our own. Theory of mind is at the heart of everything social that makes us human. Without it, we’d have a much harder time interpreting — and probably predicting — others’ behavior.
For a long time, many researchers have believed that a major reason human beings alone exhibit unique forms of communication, cooperation and culture is that we’re the only animals to have a complete theory of mind. But is this ability really unique to humans?
In a new study published in Science, my colleagues and I tried to answer this question using a novel approach. Previous work has generally suggested that people think about others’ perspectives in very different ways than other animals do. Our new findings suggest, however, that great apes may actually be a bit more similar to us than we previously thought.
Apes get some parts of what others are thinking
Decades of research with our closest relatives — chimpanzees, bonobos, gorillas and orangutans — have revealed that great apes do possess many aspects of theory of mind. For one, they can identify the goals and intentions behind others’ actions. They’re also able to recognize which features of the environment others can see or know about.