Just Babies Read Online Free Page B

smaller objects, so that they fill up the same overall space, but the skeptic can then worry that babies are responding, not to the number of objects, but to big objects versus small objects. It turns out to be exquisitely complicated to design a study that isolates just the relevant variable—but it can be done.
    The development of looking-time methods set off a revolution in how we think about the minds of babies. The first studies to use this method focused on early knowledge of physical objects—a baby’s “naive physics.” Psychologists showed babies magic tricks, events that seemed to violate some law of the universe: you remove the supports from beneath a block and it floats in midair, unsupported; an object disappears and then reappears in another location; a box is placed behind a screen, and the screen falls backward into empty space. If babies expect the world to work in accordance with the principles of physics, they should find these outcomes surprising. And their looking times show that they do—babies look longer at such scenes than at scenes that are identical in all regards except that they don’t violate physical laws. A vast body of research now suggests that—contrary to what legions of psychology undergraduates were taught for decades—babies think of objects largely as adults do, as connected masses that move as units, that are solid and subject to gravity, and that move in continuous paths through space and time.
    In a classic study, Karen Wynn found thatbabies can also do rudimentary math with objects. The demonstrationis simple. Show a baby an empty stage. Raise a screen in the middle of the stage. Put a Mickey Mouse doll behind the screen. Then put another Mickey Mouse doll behind the screen. Now drop the screen. Adults expect two dolls, and so do five-month-olds; if the screen drops to reveal one or three dolls, the babies look longer than they do if the screen drops to reveal two.
    Experimenters have also used these methods to explore babies’ expectations about people—their “naive psychology,” as opposed to their“naive physics.” We’ve long known that babies respond in a special way to other people. They are drawn to them.They like the sound of human voices, particularly those they are familiar with; they like the look of human faces. And they are disturbed when interactions don’t go the way they expect. Here’show to freak out a baby: sit across from the baby, engage with him or her, and then suddenly become still. If this goes on for more than a few seconds, with you looking all corpselike, the baby will become upset.In one study, two-month-olds were seated across from a TV screen displaying their mother. When the mother interacted with the babies by means of real-time videoconferencing, babies enjoyed it. But when there was a time delay of a few seconds, the babies became agitated.
    The psychologist Amanda Woodward designed a looking-time study to demonstrate thatbabies know that individuals have goals. First, a baby was placed in front of two objects and watched a hand reach for one of these objects. Then experimenters reversed the objects’ locations. Babies expectedthat when the hand reached again, it should go for the same object, not the same location. This expectation was special to hands; if they saw a metal claw reaching for the object, the result went away.
    In another set of studies, the psychologists Kristine Onishi and Renee Baillargeon showed thatfifteen-month-olds can anticipate a person’s behavior on the basis of his or her false belief. Babies watched as an adult looked at an object in one box, then observed the object move to another box while the adult’s eyes were covered. Later on, they expected the adult to reach into the original box, not the box that actually contained the object. This is a sophisticated psychological inference, the sort of rich understanding of other minds that most psychologists used to believe only four- and five-year-olds