Choice between reliable and unreliable reinforcement alternatives revisited: Preference for unreliable reinforcement.
A short, reliable signal can make even long-shot rewards feel worth chasing—until the wait gets too long.
01Research in Context
What this study did
Allan et al. (1994) let pigeons pick between two keys. One key always paid off. The other paid off only half the time.
The catch was the wait. After each choice, birds had to sit through a short or long delay before food arrived.
Researchers watched which key the birds pecked more. They wanted to see if unreliable food could ever beat sure food.
What they found
When the delay was short, birds strongly preferred the 50 % unreliable key. The gambling side pulled them in.
If the delay grew longer, the liking faded or flipped. Timing killed the thrill.
The signal that came right before food gained power. That little light became a mini-reward on its own.
How this fits with other research
King et al. (1990) saw the same flip four years earlier. Once they added signals, birds also turned away from the sure thing.
Lancioni et al. (2011) stretched the time between trials. Longer gaps made the unreliable key less attractive, showing a boundary.
Mazur (1995) added colored lights the next year. When the light paired with food, birds again chose lower odds. All three studies point to the same idea: stimuli that predict food can override the math.
Why it matters
Your clients also chase signals. A slot-machine jingle, a teacher’s “maybe,” or a parent’s glance can feed the behavior even when the real prize is rare.
Use this when you shape persistence. Pair a brief, clear cue with every payoff at first. Then thin the payoff but keep the cue. The cue will hold the behavior while you stretch the schedule.
Watch the wait time. If the delay to the real reward gets too long, the cue loses its magic and the learner may walk away.
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02At a glance
03Original abstract
Pigeons' choices between a reliable alternative that always provided food after a delay (i.e., 100% reinforcement) and an unreliable one that provided food or blackout equally often after a delay (i.e., 50% reinforcement) was studied using a discrete-trials concurrent-chains procedure modified to prevent choice between alternatives following a blackout outcome. Initial links were fixed-ratio 1 schedules, and terminal links were fixed-time schedules. Stimuli presented during the terminal-link delays were correlated with the food and blackout outcomes. In Experiment 1, terminal-link durations were varied. With short terminal links (i.e., 10 s), 6 of 8 subjects showed strong preference for the 50% side. As terminal-link duration increased to 30 s, preference, regardless of direction, became less extreme. In Experiment 2, the side-key location of the 50% and 100% alternatives was reversed for 3 subjects. Preference for the 50% alternative reoccurred following the key reversal. When a 5-s separation was subsequently interposed between the initial and terminal links for both alternatives, all birds reversed to a preference for the 100% side. In general, the strong preference for the 50% side was qualitatively consistent with the expectation that the procedure enhanced the conditioned-reinforcement effectiveness of the food-associated terminal-link stimulus on the 50% side. Implications of the results for various accounts of choice of the 50% alternative are discussed.
Journal of the experimental analysis of behavior, 1994 · doi:10.1901/jeab.1994.62-353