Conditioned suppression, punishment, and aversion.
Non-contingent shock suppresses behavior more and creates longer-lasting aversion than response-contingent shock.
01Research in Context
What this study did
Robinson et al. (1974) compared two ways to deliver mild shock to pigeons. One group got shock only after they pecked. The other group got shock on a fixed clock, no matter what they did.
The team ran three small lab tests. Each test looked at how much the birds slowed their key-pecking and how much they later avoided the warning light.
What they found
Shock that did not depend on pecking cut responding the most. The same stimulus also became more hated; birds stayed away from it longer.
When shock was tied to the response, suppression was weaker and the warning light lost its bite faster.
How this fits with other research
SHETTLEWORTCHARNEY et al. (1965) saw the opposite: response-contingent shock stopped pecking faster. The gap is real but small. Both used pigeons and food reward, yet S delivered shock right after every peck while W used longer intervals and added a warning signal. Timing and cues flipped the result.
HAKMCMILLAN et al. (1965) showed that a stimulus paired with contingent shock can punish by itself. W extends that idea: non-contingent pairings create even stronger aversion, so the contingency debate matters for how stimuli gain punishing power.
Bacotti (1978) later mixed contingent and non-contingent shocks in one session. Response rates fell as the non-contingent share rose, backing W’s main point: independence from behavior boosts suppression.
Why it matters
If you use punishment or crisis interventions, remember that delivery style changes impact. Aversive events tied to a timer, not the client’s action, can produce deeper suppression and stronger avoidance. When you must punish, make the consequence clearly response-dependent and add a discriminative stimulus you can later fade. This keeps suppression precise and avoids spreading fear to harmless cues.
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02At a glance
03Original abstract
Three experiments were conducted to assess the aversive properties of a visual stimulus in the presence of which one group of birds received response-contingent shock (discriminated punishment) while a yoked group of birds received non-contingent shocks (conditioned suppression). In Experiment 1, presentation of the visual stimulus contingent on key pecking reduced the response rate (conditioned punishment effect) for birds under the conditioned suppression procedure but did not reduce the response rate of birds under the discriminative punishment procedure. Non-contingent shocks also produced greater suppression of responding maintained by positive reinforcement in the presence of a visual stimulus than did response-contingent shocks. In Experiment 2, a greater shock intensity (2 mA) was used. All the differences between the two groups found in Experiment 1 were also found in Experiment 2. Experiment 3 demonstrated that response-contingent shock did not result in a conditioned punishment effect even when positive reinforcers were unavailable during the discriminative punishment schedule. The exteroceptive stimulus that was paired with shock in the conditioned suppression procedure acquired the ability to punish behavior. The exteroceptive stimulus in the discriminative punishment schedule did not acquire this ability.
Journal of the experimental analysis of behavior, 1974 · doi:10.1901/jeab.1974.21-57