In Skinner's box, what happens when the rat presses the lever?

• A. It receives food reinforcement, increasing the lever pressing.
• B. A loud alarm is triggered but no reward is given.
• C. The lever disengages and stops the experiment.
• D. It results in an electric shock every time.

Answer: (A)

Positive reinforcement strengthens a behavior when a desirable consequence follows the action. In Skinner's box, a rat pressing the lever is followed by the delivery of a food pellet. That food reinforcement makes the rat more likely to press the lever again, so lever pressing increases. This is a classic example of operant conditioning with a reinforcing outcome that motivates the behavior. The other situations describe aversive or non-reinforcing outcomes that would not promote pressing in the same way—a loud alarm with no reward is undesirable, stopping the lever would end the session, and a shock would punish and reduce the behavior.