ABA Fundamentals

Fixed-interval punishment.

Appel (1968) · Journal of the experimental analysis of behavior 1968
★ The Verdict

Punishment intensity and how often it happens control how fast behavior stops and how soon it comes back.

✓ Read this if BCBAs who use punishment or reduction procedures in clinics or animal labs.
✗ Skip if Practitioners who work only with reinforcement and no reduction plans.

01Research in Context

01

What this study did

Scientists gave rats milk for pressing a bar on a variable-interval schedule.

They then added fixed-interval electric shocks to see how the shocks changed pressing.

The team varied shock strength and how often shocks came to map the suppression curve.

02

What they found

Stronger and more frequent shocks cut pressing faster and deeper.

After shocks stopped, rats took longer to bounce back if the shocks had been intense.

The relation was orderly: more shock meant less behavior and slower recovery.

03

How this fits with other research

Kaufman (1965) saw quick recovery in humans even at high shock levels, but the rats here showed the opposite. The gap is explained by species and by giving people several shock sessions; people adapt faster.

Hake et al. (1967) first drew the intensity–suppression curve in monkeys. Appel (1968) now shows the same straight line in rats, locking in the rule across species.

Schroeder et al. (1969) moved the same VI-shock logic to adult humans one year later and found matching schedule-based suppression, proving the rule holds beyond rodents.

04

Why it matters

The study gives you a clear dial: stronger or more frequent punishers work faster but take longer to wear off. Use the weakest punisher that works and deliver it right away, as Reynolds (1968) shows delay weakens effect. Track recovery time after you cut the punisher; if behavior is slow to return, you probably used too much intensity.

Free CEUs

Want CEUs on This Topic?

The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.

Join Free →
→ Action — try this Monday

Try dropping the intensity of your punisher one notch and measure how fast behavior recovers.

02At a glance

Intervention
other
Design
single case other
Sample size
33
Population
other
Finding
negative

03Original abstract

The average rate of bar-pressing maintained by a variable-interval schedule of milk reinforcement in 33 rats was found to be a decreasing function of intensity of concurrent punishment and, over a wide range of shock intensities, was inversely related to punishment frequency. Cumulative records were, however, negatively accelerated during 30-min punishment sessions with complete suppression occurring earlier and earlier (after fewer and fewer shocks) as intensity increased. In addition, acceleration was often observed between successive fixed-interval shock presentations and, at low and moderate intensities, bursts of responding occurred after each shock. The time to recover between punishment sessions (post-punishment recovery) was an increasing monotonic function of punishment intensity.

Journal of the experimental analysis of behavior, 1968 · doi:10.1901/jeab.1968.11-803