The law of effect and avoidance: a quantitative relationship between response rate and shock-frequency reduction.

The researchers tested if Herrnstein’s matching law works for avoidance. They used rats on a VI schedule where lever presses stopped shocks from coming.

They counted how often the rats pressed and how much the presses cut shock rate.

Response rate fit the matching equation. The less shocks the rats got, the more they pressed, just like the math predicted.

Shock-frequency reduction acted like any other reinforcer.

Farmer et al. (1966) first showed that simply lowering shock rate keeps avoidance going. Lattal (1974) now gives that idea a number line.

Rose et al. (2000) later found the asymptote k moves when sucrose strength changes. This seems to clash with A’s steady k, but the 1974 study used shock reduction, not sugar. Different reinforcers can move k without breaking the law.

Bradshaw et al. (1978) and Wilkie et al. (1981) showed sucrose size or strength shifts the same curve. Together these papers say: check your reinforcer type and size before you trust one set of parameters.

If you run avoidance programs, remember rate follows reinforcement value. Increase the payoff—fewer aversive events—and behavior will rise. If behavior drifts, check if the actual reduction the client gets has changed, not just your schedule.