Babies Learn to Predict Behavior at About a Year Old

June 19, 2006 — -- To most parents, babies are a terrific mystery -- no one knows what lurks in their tiny heads or what they are doing with their flailing arms.

Researchers now say that from the eyes of a young infant, parents are just as mysterious and confusing, because according to a new study, babies younger than 6 months old cannot predict what another person is trying to do.

Swedish researchers studied 6-month-old babies, 1-year-old babies and adults, all of whom watched a video of a hand placing toys into a bucket. The 1-year-old babies and adults quickly learned to shift their gazes to the bucket when the hand picked up a toy, indicating they knew what the hand was about to do.

But the 6-month-olds did not shift their gaze. Researchers speculate that the brain uses specific neural wiring to make predictions about how people might act. At 6 months old, babies' brains don't have that wiring yet.

The findings won't help parents calm crying babies any quicker, but they might shed some light on the situation. For example, if Mommy picks up a favorite toy, a 6-month-old infant wouldn't guess that she intends to hand that toy over, even if she has done that before.

In other words, newborns do not really understand when their parents are trying to help them.

This study reminds us that babies younger than 6 months have a hard time figuring out what we intend to do, "so it is important not to misinterpret their behavior as manipulative or demanding of attention," said Dr. John Constantino, a pediatric psychiatry professor at the Washington University School of Medicine.

By the time infants are a year old, they can more easily understand how the people around them might behave.

For example, researchers found that if a 1-year-old infant saw Mommy's hand pick up a ball, he would expect Mommy to drop the ball into a bucket, because he has seen her do that before.

Researchers explain that at 12 months, the infant's brain has developed enough to understand that if he'd picked up the ball, he would put it in the bucket himself.

That sounds like a simple or minor point, but researchers indicate that it has big implications.

Infants' ability to predict someone else's behavior is related to their ability to understand their own behaviors, suggests Bennett Bertenthal, at the University of Chicago Center for Early Childhood Research. This ability is sometimes called shared intentionality. Some developmental disorders, such as autism, have been attributed to deficits in shared intentionality.

"Autistic children are first identifiable around the age of 1 year," Constantino said. This study suggests that we may not be able to identify autism any earlier, he said, because the circuitry that can produce autistic behaviors is not in place until infants "grow and develop from 6 to 18 months of age."

This finding might explain why babies who appear perfectly normal at 5 or 6 months later develop autistic symptoms. The circuitry responsible for "shared intentionality" might not develop properly in these children.

Researchers say that the true wiring of the infant brain is still unknown. What parents have to remember: Young babies don't know everything. As infants grow and develop, their brains become better able to understand the world around them and themselves.

This knowledge may not solve all of a new parent's questions, but it may help them understand a little better why children do what they do