A new study finds that babies as young as a year-and-a-half can guess what other people are thinking.
Humans are "very good at inferring other people's mental states: their emotions, their desires and, in this case, their knowledge," study author H. Clark Barrett, an anthropologist at the University of California, Los Angeles, told LiveScience. "So it could play an important role in cultural transmission and social learning."
Previously scientists thought that the ability to guess what others are thinking emerged later in childhood, reports LiveScience.
Findings were published January 29 in the journal Proceedings of the Royal Society: B.
In their experiment, researchers studied about 91 children, ages 19 months to five years, from China, Fiji, and Ecuador. The team set up a classic test called false-belief tasks. The test involves one person coming into a room and putting an object into a hiding place. A second person then walks into the room and puts the object into his pocket without the first person's realizing. Then the first person returns and another person then asks the child where he or she thinks the first person will look for the object.
LiveScience reports that the task is tricky "because the children need to have a theory of mind," or the ability to understand another's perspective. By age four to seven, most Western children (at least according to research) will say the first person will go to the original hiding place. While previous studies have looked at younger children, the researchers say the findings have been muddled by cultural differences in that the babies weren't always asked the question verbally. "In many societies, parents don't make a habit of asking children rhetorical questions like, ‘What is the cow doing?' when the adults already know the answer," reports LiveScience.
In the latest study, researchers both posed the question and looked at babies' eye movements to gather whether or not they understood the role play, with the young subjects consistently glancing at the hiding place.