Actual versus potential shock in making shock situations function as negative reinforcers.
Negative reinforcement works only when the person actually experiences fewer aversive events, not merely has the chance to avoid them.
01Research in Context
What this study did
Peterson (1968) worked with lab monkeys. The animals could press a lever to postpone mild electric shocks.
Two shock schedules ran side-by-side. One group could truly cut the number of shocks they felt. The other group got the same total shocks, just spread out.
What they found
Monkeys that really received fewer shocks kept pressing hard. Monkeys that only rearranged the same number of shocks soon stopped pressing.
Responding lived or died by the actual shock rate, not by the chance to avoid.
How this fits with other research
Zeiler (1977) extends the story. Even when shock rate stayed flat, monkeys still worked if the lever turned off a warning light on a fixed-ratio schedule. The 1968 paper shows avoidance needs true rate cuts; the 1977 paper shows stimulus termination alone can keep responding when the schedule is FR.
Lattal (1974) used the same lab set-up but mixed food and shock cues. Both studies prove shock schedules are handy for testing basic principles, yet each asks a different question.
Murphy (1993) adds the ethical lens. The 1968 study merely maps the mechanism; Glynis warns that any real-world use of aversives demands clear consent and client benefit.
Why it matters
When you use escape or avoidance procedures, check that the client truly experiences fewer aversive events, not just a new rule. If the headache stays the same, the behavior will fade. Track actual reductions, not potential opportunities, and always pair the plan with informed consent.
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02At a glance
03Original abstract
The relative importance of potential and actual shocks in making shock situations function as negative reinforcers was studied. Shocks were scheduled to occur at the same rate during two stimuli. During one, squirrel monkeys could avoid the shocks; during the other, they were unavoidable. For the two stimuli the potential rate of shocks was the same, but the actual rate was lower during avoidance because of avoidance responding. Fixed-ratio responding was maintained by the change from unavoidable shock to avoidance, indicating that the change was reinforcing when it resulted in a reduction in actual shock rate with no reduction in potential shock rate. Further increases in the rate of potential shock during avoidance had little effect upon the fixed-ratio responding until the rate was increased to the point that the actual shock rate during avoidance was comparable with that during unavoidable shock. At that point, the fixed-ratio response rate decreased nearly to zero. These findings show that actual shocks are more important than potential shocks in determining whether or not a shock situation will function as a negative reinforcer; this explains why the change from unavoidable shock to avoidable shock is reinforcing.
Journal of the experimental analysis of behavior, 1968 · doi:10.1901/jeab.1968.11-385