Most animal trainers utilize a theory called operant conditioning when working with exotic animals. Operant conditioning, a theory created by psychologist B.F. Skinner, is a fundamental concept in behavioral psychology.
With operant conditioning, trainers teach animals to connect a behavior with a cue (or signal), and then reward the animal for correct behavior. Whenever the animal behaves in the desired way -- or even close to the desired way -- the trainer offers positive reinforcement (usually in the form of food). Skinner called this method capturing. The idea is that positive reinforcement of a seemingly random behavior increases the likelihood of it happening again. Applying a technique called shaping helps refine the behavior.
Let's look at an example: You're a lion trainer and you want to train a lion to turn in a circle to the right when you snap your fingers. Using operant conditioning, you'd reward the lion for any small movement to the right. Some trainers use a target to help shape this behavior -- perhaps a long stick or pole. The lion might touch its nose to the end of the pole and get a reward. Then you'd begin moving the pole in a circular motion, providing reinforcement as the lion follows the target. Eventually the lion will follow the target to move in a complete circle.
Next, you'd use classical conditioning to train the lion to turn at your finger-snap cue, instead of following the target, by associating the behavior with the snapping of your fingers. Soon the lion will turn when you snap your fingers.
If you're a dog owner, these training techniques probably sound familiar. But dogs are domesticated animals. Lions are not. Is a wild animal ever really tame? Read on to find out why the answer generally is "no."