Punishment of elicited aggression.

The team worked with monkeys that bit each other after receiving a mild shock. They wanted to know if a second, stronger shock could stop the biting.

Each time a monkey bit, the staff gave an immediate shock through the cage floor. They slowly raised the shock level across sessions.

Biting dropped as the punishment shock got stronger. At the highest level, attacks almost stopped.

The same stimulus that first caused the aggression could also end it when used as a punisher.

Schroeder et al. (1969) saw the same pattern in rats. Shock given right after pain-elicited aggression cut the behavior, but the effect vanished when punishment ended.

Reynolds (1968) warned that delay weakens punishment. Azrin (1970) kept the shock immediate, so only moderate intensity was needed.

Vukelich et al. (1971) later showed a twist: very strong, rare shocks can actually increase biting. The 1970 study sits in the safe middle zone—strong enough to suppress, not so sparse that aggression rebounds.

You now have lab proof that contingent, immediate consequences can override even reflexive aggression. In practice, this supports zero-delay, response-based interventions for severe SIB or aggression. Pair the consequence with a functional replacement skill and fade it fast, because punishment gains vanish once it stops.