The relative aversiveness of signalled versus unsignalled shock-punishment.
A short warning before mild punishment keeps behavior going better than surprise punishment.
01Research in Context
What this study did
Macdonald (1973) worked with lab rats pressing a lever for food.
Sometimes the next food also brought a mild electric shock.
Half the time a tone warned the rat first; half the time the shock came with no cue.
The team counted how much the warning tone changed the rat’s pressing.
What they found
Rats kept pressing more when a tone warned them shock was coming.
Without the tone, the same shock almost stopped the pressing.
The simple signal made the punishment feel less bad.
How this fits with other research
Badia et al. (1972) saw the same thing a year earlier.
Their rats even worked to keep the warning tone on, showing the effect is strong.
Two 1973 follow-ups pushed it further: Liberman et al. (1973) showed rats still picked the warning even when it meant longer or stronger shocks, and Liberman et al. (1973) showed they picked it even when it meant more shocks overall.
Yet Hearst et al. (1970) looked like the opposite: their warning tone made rats freeze and get more shocks.
The difference is task. E’s rats were trying to avoid shock; freezing hurt them.
L’s rats were working for food; the tone simply told them when to expect the extra cost.
Hymowitz (1981) also found mixed results, but used higher shock and different responses, showing the signal benefit isn’t magic—procedure matters.
Why it matters
If you ever use response cost or time-out, give a clear warning first. A two-second “Points loss in 3-2-1” can cut the punitive bite without weakening the lesson. The rat data says predictability beats intensity, so save your loudest consequences for times you can announce them.
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02At a glance
03Original abstract
Six rats were trained on a two-component multiple schedule with each component consisting of a two-link chain schedule. Differential response suppression in the two initial links, as well as in the two terminal links of the chain schedules, was used as a measure of the relative aversiveness of stimulus events in the two terminal links. When signalled and unsignalled shock-punishment (in addition to equal numbers of food reinforcers) were scheduled in the separate terminal links, subjects responded at lower rates in the initial link preceding unsignalled shock-punishment than in the initial link preceding signalled shock-punishment. Similarly, subjects responded at lower rates in the terminal link containing unsignalled shock-punishment than in the terminal link containing signalled shock-punishment. Reversing the terminal-link positions of signalled and unsignalled shock-punishment led to a reversal of the differential response suppression in the two initial and the two terminal links of the chain schedules. These results indicate that signalled punishment is relatively less aversive than unsignalled punishment and support an "information hypothesis", which assumes that a condition in which information is provided about the onset of environmental events, even negative events such as shock punishment, is more reinforcing than a condition in which such information is absent.
Journal of the experimental analysis of behavior, 1973 · doi:10.1901/jeab.1973.20-37