Reading Your Baby's Mind

Part of that empathy may come from another early-baby skill that's now better understood, the ability to discern emotions from the facial expressions of the people around them. "Most textbooks still say that babies younger than 6 months don't recognize emotions," says Diane Montague, assistant professor of psychology at LaSalle University in Philadelphia. To put that belief to the test, Montague came up with a twist on every infant's favorite game, peekaboo, and recruited dozens of 4-month-olds to play along. She began by peeking around a cloth with a big smile on her face. Predictably, the babies were delighted, and stared at her intently--the time-tested way to tell if a baby is interested. On the fourth peek, though, Montague emerged with a sad look on her face. This time, the response was much different. "They not only looked away," she says, but wouldn't look back even when she began smiling again. Refusing to make eye contact is a classic baby sign of distress. An angry face got their attention once again, but their faces showed no pleasure. "They seemed primed to be alert, even vigilant," Montague says. "I realize that's speculative in regard to infants... I think it shows that babies younger than 6 months find meaning in expressions."

This might be a good place to pause for a word about the challenges and perils of baby research. Since the subjects can't speak for themselves, figuring out what's going on inside their heads is often a matter of reading their faces and body language. If this seems speculative, it's not. Over decades of trial and error, researchers have fine-tuned their observation skills and zeroed in on numerous consistent baby responses to various stimuli: how long they stare at an object, what they reach out for and what makes them recoil in fear or disgust can often tell experienced researchers everything they need to know. More recently, scientists have added EEGs and laser eye tracking, which allow more precise readings. Coming soon: advanced MRI scans that will allow a deeper view inside the brain.

When infants near their first birthdays, they become increasingly sophisticated social learners. They begin to infer what others are thinking by following the gaze of those around them. "By understanding others' gaze, babies come to understand others' minds," says Andrew Meltzoff, a professor of psychology at the University of Washington who has studied the "gaze following" of thousands of babies. "You can tell a lot about people, what they're interested in and what they intend to do next, by watching their eyes. It appears that even babies know that... This is how they learn to become expert members of our culture."

Meltzoff and colleague Rechele Brooks have found that this skill first appears at 10 to 11 months, and is not only an important marker of a baby's emotional and social growth, but can predict later language development. In their study, babies who weren't proficient at gaze-following by their first birthday had much less advanced-language skills at 2. Meltzoff says this helps explain why language occurs more slowly in blind children, as well as children of depressed mothers, who tend not to interact as much with their babies.

In fact, at just a few months, infants begin to develop superpowers when it comes to observation. Infants can easily tell the difference between human faces. But at the University of Minnesota, neuroscientist Charles Nelson (now of Harvard) wanted to test how discerning infants really are. He showed a group of 6-month-old babies a photo of a chimpanzee, and gave them time to stare at it until they lost interest. They were then shown another chimp. The babies perked up and stared at the new photo. The infants easily recognized each chimp as an individual--they were fascinated by each new face. Now unless you spend a good chunk of your day hanging around the local zoo, chances are you couldn't tell the difference between a roomful of chimps at a glance. As it turned out, neither could babies just a few months older. By 9 months, those kids had lost the ability to tell chimps apart; but at the same time, they had increased their powers of observation when it came to human faces.

Nelson has now taken his experiment a step further, to see how early babies can detect subtle differences in facial expressions, a key building block of social development. He designed a new study that is attempting to get deep inside babies' heads by measuring brain-wave activity. Nelson sent out letters to the parents of nearly every newborn in the area, inviting them to participate. Earlier this summer it was Dagny Winberg's turn. The 7-month-old was all smiles as her mother, Armaiti, carried her into the lab, where she was fitted with a snug cap wired with 64 sponge sensors. Nelson's assistant, grad student Meg Moulson, began flashing photographs on a screen of a woman. In each photo, the woman had a slightly different expression--many different shades of happiness and fear. Dagny was given time to look at each photo until she became bored and looked away. The whole time, a computer was closely tracking her brain activity, measuring her mind's minutest responses to the different photos. Eventually, after she'd run through 60 photos, Dagny had had enough of the game and began whimpering and fidgeting. That ended the session. The point of the experiment is to see if baby brain scans look like those of adults. "We want to see if babies categorize emotions in the ways that adults do," Moulson says. "An adult can see a slight smile and categorize it as happy. We want to know if babies can do the same." They don't have the answer yet, but Nelson believes that infants who display early signs of emotional disorders, such as autism, may be helped if they can develop these critical powers of observation and emotional engagement.