Preference for mixed- versus fixed-ratio schedules.

Fantino (1967) let pigeons choose between two keys. One key gave a mixed-ratio schedule. The other gave a fixed-ratio schedule with the same average payoff.

The birds could switch keys at any time. The team recorded which key the bird pecked more.

The pigeons usually picked the mixed-ratio key. They did this even when both keys paid off at the same rate.

Preference flipped only when the fixed-ratio key clearly paid more.

Mullane et al. (2017) later saw the same pattern in kids. Children chose to do math problems under a mixed schedule that tossed in an easy FR-1 now and then.

Mellott et al. (2023) stretched the idea to duration. Students also liked mixed-duration schedules and worked harder because of it.

HERRNSTEISLOANE (1964) set the stage by showing pigeons prefer variable intervals. Fantino (1967) moved the question to ratio schedules and proved the variability effect still holds.

If your client can pick the task, slip a tiny ratio into the mix. A single easy response that earns a token can make the whole job feel better. The learner may stay longer and need less prompting, even when the overall work stays the same.