Humans are known to invent private hand gestures. Chimps in the wild do, too, a new study suggests. By Brandon Keim Parents and their children, or people who know each other well, often share some ...

Chimps may revise their beliefs in surprisingly human-like ways. Experiments showed they switched choices when presented with stronger clues, demonstrating flexible reasoning. Computational modeling ...

When Aristotle claimed that humans differ from other animals because they have the ability to be rational, he understood rational to mean that we could form our views and beliefs based on evidence, ...