Punishment of shock-induced aggression.
Shock delivered right after biting quickly halts shock-provoked aggression, but the effect flips on and off with the contingency.
01Research in Context
What this study did
Scientists shocked squirrel monkeys’ tails to make them bite a rubber hose.
Each time a monkey bit, the team gave a quick shock to the animal’s teeth.
They ran an ABAB design: baseline, punishment, back to baseline, punishment again.
What they found
Bite-contingent shock stopped the attack right away.
When punishment paused, biting came back.
When punishment returned, biting dropped again.
How this fits with other research
Thomas et al. (1968) showed that stronger tail shocks make monkeys bite more.
The new study flips the script: shock for biting makes biting stop.
Together they show the same stimulus can elicit or suppress aggression, depending on where it lands in the response chain.
Hake et al. (1967) found that low-level shock only partly cuts squirrel-monkey lever pressing.
Here, shock for biting wiped out the aggressive response.
The sharper effect may be because attack behavior is less practiced than food lever pressing.
Why it matters
The study is a clean lab demo that punishment can shut down reflexive aggression.
It reminds you that contingency, not just intensity, drives suppression.
In practice, pair any mild punisher you use with clear response-contingent rules and watch for return when the punisher lifts.
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02At a glance
03Original abstract
Squirrel monkeys were restrained in a chair equipped with a tail-shock apparatus and a pneumatic bite hose located in front of the subject's face. An aggressive response was recorded when the monkey bit the hose. Initial sessions in which no shocks were delivered produced some biting. When biting during these sessions stabilized at a near-zero level, regularly scheduled shocks were delivered to the monkey's tail, causing a consistently higher rate of biting. After several sessions under these conditions, a punishment phase was introduced in which the previous shock conditions were maintained, and every bite was followed immediately by another, more intense shock. Biting under these conditions was suppressed to a near-zero level. When the punishment contingency was removed, biting increased. With one subject, two additional bite-contingent stimuli were examined: (1) a milder shock that, when made contingent upon hose biting, also suppressed that response, and (2) a contingent tone that had no obvious suppressing or facilitating effect. Individual differences among subjects were extreme, but the effect of bite-contingent shock was consistent. Observations of the subjects during the punishment sessions indicated the existence of certain side effects that resulted from the use of punishment to suppress shock-induced aggression.
Journal of the experimental analysis of behavior, 1969 · doi:10.1901/jeab.1969.12-1009