Dog training typically centers on operant conditioning. The first scientist to define this concept was B.F. Skinner, who studied the work of Russian physiologist Dr. Ivan Pavlov on animal behavior. In Pavlov's groundbreaking study, dogs learned that a stimulus (in this case, a bell) meant they were about to be fed. Starting with two things that are naturally paired -- salivating and being fed -- Pavlov added a third component by ringing a bell before feeding. After a few trials, the dogs learned to associate the bell with being fed and would react by salivating at the sound of the bell in anticipation of their food but without any food present.
Since dogs naturally begin salivating when offered food, food is an unconditioned stimulus. No conditioning or special training is necessary to cause the dog to salivate, which is an unconditioned response. In contrast, a ringing bell does not normally cause dogs to salivate; they will do so only if they have been conditioned to associate a bell with being fed. Therefore, the bell is a conditioned stimulus. The dog's new reaction is a reflex to the stimulus and is a conditioned response.
Many of us see this today with our own dogs when they break into a frenzy of barking at the sound of the doorbell, sometimes even a doorbell on television. In this case, the dog has been conditioned to associate the stimulus of the bell with the imminent arrival of a stranger.
When we see flashing lights or hear a siren behind us while driving, we may reflexively tense up and our heart rate may increase. We have been conditioned to associate the sound of sirens with the unpleasant and stressful experience of getting a ticket. This is classical conditioning. Both animals and people can learn to relate a pair of events and respond to the first in anticipation of the second. This type of learning is passive and involuntary; it occurs without the learner doing anything and often without awareness.
While Pavlov's work dealt with a reflexive reaction to a conditioned stimulus, Skinner became interested in creating a specific behavioral reaction to a stimulus by adding a reinforcer. A reinforcer can be either a reward or a punisher. A reward is anything that increases the frequency of an action; a punisher is anything that decreases its frequency.
When we are rewarded for a certain behavior, we are likely to repeat that behavior. When we are punished for a certain behavior we are likely to stop. This type of learning is active and voluntary; it depends on the actions of the learner.
Because the definition of a reinforcer is based on its effectiveness, it's important to remember that a reward for one person may not be meaningful, and thus not a reward, for another. Similarly, what is a reward in one context may not be somewhere else.
Skinner showed that both animals and people would perform certain behaviors for a reward. In his experiments with rats and pigeons, Skinner showed how animals could learn to press a lever to get a food reward. When the animals were first introduced to the test box they moved around randomly. When they accidentally depressed the lever, a food pellet was dispensed. They quickly learned to depress the lever on purpose to get a pellet. He also shaped behaviors that are more complicated by reinforcing them step by step. Skinner called his approach "operant conditioning" because the animal's behavior actually operated on the environment (pressing the lever) in response to the anticipated outcome (getting a food reward).
Rewarding to encourage good behavior and punishing to discourage bad is something most of us do instinctively; it's common sense. Operant conditioning had a long history in animal training even before it was ever defined. Colonel Konrad Most, who published "Training Dogs: A Manual" in 1910, was using many of the same principles that Skinner studied, decades before he described them. Col. Most's training methods seem somewhat harsh by today's standards, but he is considered by many to be the father of modern dog training. Most, and other trainers used both rewards and punishers to shape and reinforce desired behavior.
Next, we'll look at how reinforcers are used in animal training.