We learn by associating things with other events, this is called classical conditioning. A neutral stimulus comes to evoke the response usually evoked by another stimulus by being paired repeatedly with the other stimulus.

Taste aversion is an example of classical conditioning. These aversions help organisms avoid harmful foods. Only association may be required. Nausea seems to stem from poisoned food. Once a person gets sick from something he ate, he will not eat it again.

We also learn by higher-order conditioning. This occurs when a previously neutral stimulus comes to serve as a conditioned stimulus after repeatedly being paired with a stimulus that has already become a CS.

Operant conditioning is avoiding something that was once harmful or fearful. People learn to or not to do things because of the consequences. Operant conditioning focuses on what organisms do about their environments.

The law of effect explains that a response is "stamped in" or strengthened in a particular situation by a reward. Bad behavior can also be rewarded negatively. OC is active while CC is a passive learning. OC has both negative and positive reinforcers.