Choice with uncertain outcomes: conditioned reinforcement effects.
A fast signal can make lean schedules as attractive as rich ones—timing beats probability.
01Research in Context
What this study did
King et al. (1990) let pigeons choose between two keys. One key always paid off. The other key paid off only half the time.
Sometimes a light flashed to show which outcome was coming. Sometimes the birds had to wait in the dark. The team watched how the birds voted with their beaks.
What they found
Without signals, the birds almost always picked the sure thing. When a light tipped them off about the uncertain outcome, most birds flipped and gambled instead.
The longer the wait before payoff, the weaker the flip. Signals plus short waits made gambling look good.
How this fits with other research
Allan et al. (1994) ran almost the same vote and got the same flip. Short waits plus signals made the 50 % key the hot favorite. Both labs show timing is the dial that turns preference.
McLean et al. (1981) saw rats always pick signaled food. Funderburk et al. (1983) found the rat vote can flip if the signal is too short or the rat is locked in. These studies line up: signals pull choice, but only under the right wait and lock-in rules.
Vaughan (1985) showed pigeons care more about delay than probability. King et al. (1990) add the twist: a quick flash can make probability matter less, turning the delay rule upside down.
Why it matters
Your clients, like pigeons, vote with their behavior. If you want them to stick with a lean schedule, pair it with a clear, quick signal and keep the wait short. If you want them to flee the gamble, drop the signal or stretch the delay. Next time you thin reinforcement, test a brief auditory cue right before the rare payoff—you may keep engagement without thickening the schedule.
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02At a glance
03Original abstract
Pigeons responded on concurrent chains with equal initial- and terminal-link durations. In all conditions, the terminal links of one chain ended reliably in reinforcement; the terminal links on the alternative chain ended in either food or blackout. In Experiment 1, the terminal-link stimuli were correlated with (signaled) the outcome, and the durations of the initial and terminal links were varied across conditions. Preference did not vary systematically across conditions. In Experiment 2, terminal-link durations were varied under different stimulus conditions. The initial links were variable-interval 80-s schedules. Preference for the reliable alternative was generally higher in unsignaled than in signaled conditions. Preference increased with terminal-link durations only in the unsignaled conditions. There were no consistent differences between conditions with and without a common signal for reinforcement on the two chains. In the first series of conditions in Experiment 3, a single response was required in the initial links, and the stimulus conditions during 50-s terminal links were varied. Preference for the reliable outcome approached 1.0 in unsignaled conditions and was considerably lower (below .50 for 3 of 5 subjects) in signaled conditions. In a final series of signaled conditions with relatively long terminal links, preference varied with duration of the initial links. The results extend previous findings and are discussed in terms of the delay reduction signaled by terminal-link stimuli.
Journal of the experimental analysis of behavior, 1990 · doi:10.1901/jeab.1990.53-201