Washington, September 17 : Babies as old as 12 to 18 months not only observe what is going on around them, but also use their own visual self-experience to judge what other people can and cannot see, according to a new study.
"This research shows how infants are using their own experiences to understand the inner lives of other people," said Andrew Meltzoff, co-director of the University of Washington's Institute for Learning and Brain Sciences.
"One of the most interesting puzzles in child development is how infants and young children come to understand other people's emotions, thoughts and inner feelings. They can see another person's body move, but they can't see into another person's heart and mind. How do babies get from observing body movements to making attributions about internal thoughts and feelings? This research indicates that a key is that they use themselves as a model for understanding others. They assume that what affects them in a certain way, also affects others in that same way. It's a good bet, and it works," added Meltzoff, who holds the Job and Gertrud Tamaki endowed chair.
For their study, Meltzoff and his colleague Rechele Brooks used a behaviour called gaze following, which refers to a baby or an adult looking where another person has just looked.
The researchers point out that detecting the direction of another person's glance is an important component of human social interactions, and that gaze following boosts an infant's early vocabulary growth and emotional understanding.
"You can learn a lot by watching other people. Gaze following also provides a social way of learning about the world and that what other people are interested in matters," said Brooks.
With a view to determining that infants use their self-experience to judge what people can see, the researchers devised a pair of experiments using ordinary and specially made blindfolds.
In one experiment, the researchers made 96 one-year-olds - half boys and half girls - with a piece of black cloth that was placed under a series of toys in front of them on a table.
One third of the infants were randomly put in a group that received no more play time. The other babies were divided into two other groups that received special play time with the cloth.
While one group played a game in which a researcher held a black blindfold in front of the children's eyes to block their view of interesting toys on the table, the other group played the same game with their being a large hole cut in the blindfold held in front of them.
The researchers finally put on a blindfold and turned toward a toy either to the left or right.
The babies who only had played with the cloth flat on the table, and those who had been exposed to the blindfold with the window in it, followed the gaze of the researcher as though she could see the toy.
The infants who were exposed to the real blindfold experience, however, spent little time following the gaze of the researcher, presumably thinking the blindfolded person could not see just as they could not see when the blindfold blocked their view of the toys.
During these games, children learned that "an opaque cloth blocks their own perception and they immediately generalized this to others, a very early form of role-taking. This illustrates that infants treat others as 'like me'," said Meltzoff.
In another experiment, the researchers made 72 18-month-olds played with a black cloth. The babies were randomly assigned to two groups, one that played with a regular blindfold, and the other with a trick blindfold that had a special see-through mesh sewn into it that allowed them to see a toy when it was held up to their eyes.
Only infants who played with the see-through blindfold followed the gaze of the researcher, when she put on the blindfold and turned toward a toy.
"If they can see through the blindfold, they assume the other person can see through it as well. In both experiments the only difference is what the children experienced in training. It appears babies are taking in information and applying it to others," said Brooks.
The researchers say that their work attains significance because it uncovers a crucial mechanism that babies use to understand the social-emotional lives of others. "The babies are using their own self-experience to interpret the behavior of others. They are making a bet: You are 'like me' and so my own experiences apply to you. By learning about themselves, they are coming to understand us. This is a fundamental life-lesson and one that begins well before they enter kindergarten," said Meltzoff
The study has been reported in the journal Developmental Psychology.