托福口语 Task 3

The concept of 'behavioral momentum' refers to the tendency of a behavior to persist even when reinforcement is reduced or removed. In psychology, behavioral momentum is analogous to physical momentum: just as a moving object resists changes in its velocity, a behavior that has been consistently reinforced in a particular context becomes resistant to extinction. This resistance is stronger when the behavior has been reinforced with a high rate and variety of reinforcers in that context. Researchers study this phenomenon by altering reinforcement schedules and observing how long the behavior continues before it stops.

Professor: Let me give you an example from a study with pigeons. In the experiment, pigeons were trained to peck a key in two different contexts. In one context, they received a food pellet every time they pecked—a continuous reinforcement schedule. In the other context, they received food only occasionally, like every fifth peck on average. After training, the researchers suddenly stopped giving food in both contexts—this is extinction. Now, what do you think happened? The pigeons in the continuous reinforcement context stopped pecking very quickly. But the pigeons in the occasional reinforcement context kept pecking for a much longer time. Why? Because their pecking behavior had built up more 'momentum' due to the higher rate of reinforcement in that context. So even when food was no longer delivered, the behavior persisted longer. This illustrates how behavioral momentum works in a real setting.