There are two kinds of conditioning—classical and operant. In classical conditioning, something that normally doesn’t have any influence becomes a trigger for a response. If you are taking a shower and someone flushes the toilet, which then causes the water to become a scalding torrent, you become conditioned to recoil in terror the next time you hear the toilet flush while lathering up. That’s classical conditioning. Something neutral—the toilet flushing—becomes charged with meaning and expectation.
