ABA Fundamentals

Negative reinforcement as shock-frequency reduction.

Herrnstein et al. (1966) · Journal of the experimental analysis of behavior 1966
★ The Verdict

Avoidance holds up when the behavior lowers the total rate of aversive events, even with no warning signal.

✓ Read this if BCBAs writing avoidance or safety protocols in clinics or animal labs.
✗ Skip if Clinicians who only use positive reinforcement and never touch aversive control.

01Research in Context

01

What this study did

The team worked with lab rats pressing a lever.

They gave shocks at random times.

Pressing the lever did not stop every shock.

It only lowered the total number of shocks per hour.

No buzzer or light warned the rat.

02

What they found

The rats learned to press.

More shock reduction meant more pressing.

When shock reduction stopped, pressing slowed.

The size of the drop matched how much shock had been saved.

03

How this fits with other research

Lambert et al. (1973) ran the same setup but added a twist.

They gave one shock right after each lever press.

The rats still pressed because five future shocks were cancelled.

This backs up the 1966 claim: cutting shock rate is the key reinforcer.

Delprato (2001) disagrees on paper.

That article says other things can also reinforce avoidance.

Yet no data are shown; it is a theory piece.

Navarick et al. (1972) adds a footnote.

During extinction some lever bites are just shock-elicited attacks, not true avoidance.

So count bursts after shocks with care.

04

Why it matters

You can maintain safety behaviors without warning stimuli.

If a client’s action lowers future aversive events, the action will persist.

Check that the plan truly cuts the overall rate of the aversive event.

Track both the target response and any post-event bursts to avoid false counts.

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Graph the real rate of the aversive event before and after the client’s response to see if the rate actually drops.

02At a glance

Intervention
other
Design
single case other
Sample size
16
Population
other
Finding
positive

03Original abstract

Is a conditioned aversive stimulus necessary in avoidance conditioning? Or is a reduction in the rate of aversive stimulation alone sufficient to generate and maintain an avoidance response? Rats were subjected to an avoidance procedure in which shocks occurred randomly in time, but a response could reduce the overall rate of shock. Fifteen acquisition curves, obtained from 16 animals, showed both immediate and delayed, rapid and gradual increases in response rate; there was no representative acquisition curve. Response rates were directly related to the amount by which the response reduced shock frequency. In extinction, when shock rates were not affected by responding, the response total was inversely related to the amount by which the response had reduced shock frequency during prior conditioning, with as many as 20,000 extinction responses when the shock frequency reduction had been relatively small. Responding on this procedure shows that avoidance conditioning can occur without benefit of either classical exteroceptive stimuli or covert stimuli inferred from the temporal constancies of a procedure. It also shows that reduction in shock rate is alone sufficient to maintain avoidance.

Journal of the experimental analysis of behavior, 1966 · doi:10.1901/jeab.1966.9-421