Question

Nancy has a headache; she takes some aspirin, and the headache goes away. Nancy is more likely to take aspirin again. This is an example of

Answer 1

The situation  is an example of negative reinforcement.

In the condition of negative reinforcement, a stimulus especially an unpleasant stimulus is removed due to a particular behavior of the person. In this case, the unpleasant behavior is the headache, and taking aspirin is a behavior of Nancy, which cut of the stimuli, that is pain relieving. In negative reinforcement a particular behavior is increased, in order to remove the unpleasant stimulus.