The differential reinforcement theory asserts that behavior is strengthened when ________ is/are applied.

In the Understanding Criminal Behavior material, the manual explains that differential reinforcement theory, as summarized by Ronald Akers, holds that people learn social behavior through operant conditioning. Behavior is reinforced when positive rewards are gained or when punishment is avoided. The manual specifically states that behavior is reinforced when positive rewards are gained, which is positive reinforcement, and it is weakened by punishment or loss of reward. It also contrasts punishment with reinforcement by noting that reinforcement accentuates positive behavior, whereas punishment tends only to suppress behavior temporarily unless constantly applied. Because the question asks what strengthens behavior, positive reinforcement is the best and most direct answer under the manual’s discussion of conditioning and reinforcement.