Psychology MCAT Practice Exam

Fixed ratio schedules and variable ratio schedules are both types of partial reinforcement schedules that significantly influence behavior, particularly in how often and under what conditions a behavior is reinforced. The correct answer is grounded in the consistency of reinforcement delivery in these two schedules.

In a fixed ratio schedule, reinforcement is provided after a set number of responses. For example, a rat might receive a food pellet after every 10 presses of a lever. This predictability leads to a high, steady rate of responding, as the subject knows exactly how many responses are needed to receive the reward.

In contrast, a variable ratio schedule entails a more unpredictable reinforcement pattern, where reinforcement is delivered after a varying number of responses around a certain average. For instance, a rat might receive a food pellet after 7 presses on some occasions and after 13 presses on others, with an average of 10 presses required. This inconsistency tends to create a high rate of responding as the subject continuously aims to achieve the elusive reward, without knowing precisely when it will arrive.

The critical distinction lies in the nature of these reinforcement schedules. Fixed ratio schedules are characterized by their consistency in the number of responses required for reinforcement, which leads to a predictable, often rapid and high, rate of responses. In contrast