In simple creatures and complex ones, learning comes in several forms. Both you and the cat look up when your roommate sneezes. But during allergy season, when she’s sneezing all the time, you and the cat both learn that sneezes are part of the normal acoustic environment and cease responding to every “a-choo”—a form of learning called habituation.
Both you and the sea slug—and virtually every other animal—are also skilled at learning “what goes with what.” If, just a couple of times, a light pressure on your skin is followed by a blast of cold air, soon you’ll brace for the chill the moment you feel the pressure. Likewise, if the sea slug feels a mild poke and then, a moment later, a slight electric shock, the slug quickly learns to shift into a defensive posture as soon as it feels the poke. This form of learning is called classical conditioning.
And what about that dancing chicken? In nature, chickens scratch, peck, and waggle their heads, but they don’t dance. Using operant conditioning, however, you can transform a chicken’s natural antics into stomps, shuffles, and hops. First identify a reward—such as corn—that your chicken likes. Then, through processes described, you initially reward behaviors that vaguely resemble a tap-dance step—say, mere scratching—and then slowly shape these scratches into smooth moves.
You can use similar techniques to train one of your professors to lecture to only one side of the room—an exercise in behavior control cherished by generations of psychology students. In this case, the reward is not food, but the favor of your and your classmates’ gaze. The procedure is simple: Conspire with your fellow students to look up with rapt attention whenever your professor addresses one side of the room, and to gaze downward and look bored whenever the prof turns in the other direction. After just a bit of this “training,” your professor—like the chicken—will be producing the behavior you’ve selected.
These simple forms of learning—habituation, classical conditioning, and operant conditioning— are crucial for many aspects of our behavior and emotional responses, as they are for many other creatures on the planet. We’ll look at how these types of learning proceed, and consider some of the biological mechanisms that—in you, the cat, the slug, or the chicken—make this learning possible. We’ll then turn to some ways in which your learning differs from that of other creatures. For example, ani-mals differ in how well they can learn just by watching their neighbors—and humans are especially skilled in this observational learning. At the same time, other creatures show feats of learning that humans can’t match, such as easily learning to navigate in new environments.