| Term | Definition |
| trephination | carving holes through the skull |
| Wilhelm Wundt | set up the first psychological laboratory and used introspection |
| introspection | asking subjects to record accurately their cognitive reactions to simple stimuli |
| structuralism | the idea that the mind operates by combining subjective emotions and objective sensations |
| William James | he is known for functionalism by examining Wundt's discoveries |
| Max Wertheimer | a gestalt psychologist who argued against dividing human thought and behavior into discrete structures |
| John Watson | a behaviorist who studies the pioneering conditioning experiments of Ivan Pavlov |
| B. F. Skinner | a behaviorist who included the idea of reinforcement to behaviorism |
| Carl Rogers | a humanist who stressed individual choice and free will |
| behaviorist | they explained human thought and behavior in terms of reward and punishment |
| cognitive psychologist | they examined human thought and behavior in terms of how we interpret environmental events |