AP Psychology Practice Test

What is a primary reinforcer?

1. A stimulus that is effective through learning

2. An innately reinforcing stimulus satisfying a biological need

3. A stimulus reinforcing a response only after a specified time has elapsed

4. An event that increases the likelihood of a behavior by its removal

The correct answer is: An innately reinforcing stimulus satisfying a biological need

A primary reinforcer is defined as an innately reinforcing stimulus that satisfies a biological need. This means that primary reinforcers are naturally reinforcing without the need for any prior learning or conditioning. Common examples include food, water, warmth, and shelter—each of which fulfills essential survival needs for individuals. In contrast, other options describe different concepts within the realm of behavioral psychology. A stimulus that is effective through learning refers to secondary reinforcers, which gain their reinforcing properties through association with primary reinforcers. Similarly, a stimulus that reinforces a response only after a specified time has elapsed describes a type of schedule of reinforcement, specifically fixed interval or variable interval, which pertains to the timing of reinforcement rather than its innate quality. Lastly, the idea that an event increases the likelihood of a behavior by its removal pertains to negative reinforcement, which involves the removal of an aversive stimulus rather than the presentation of an innate biological need. Thus, the description of a primary reinforcer as satisfying a biological need is what makes answer B the correct choice.