Assessment of preference for varied versus constant reinforcers.

Smith et al. (1997) asked seven children with autism to choose between two setups. One pile held the same top-ranked edible every time. The other pile rotated several lower-ranked edibles.

An alternating-treatments design quickly switched the piles across short sessions. The team recorded which pile the child approached first and consumed more of.

Four kids reliably went for the mixed, lower-quality pile. One child picked the constant high-quality item. Two others showed no clear winner.

Overall, variety beat the single best item about half the time.

Storch et al. (2012) later saw the same pattern during long work blocks. They added a twist: after a few minutes they paired two so-so items. Responding jumped, then the therapist returned to the top item. Their positive result lines up with G et al.—variety can recharge motivation.

Fullana et al. (2007) stretched the question to typically developing preschoolers. Using the same alternating design, they again found that changing edibles held kids’ attention better than one favorite snack. This extends the 1997 finding beyond autism.

Butler et al. (2021) looked at stability instead of variety. They tracked the same items for a year and found edible choices stayed firm while leisure and social options drifted. Their data remind us that edible variety works because those preferences are steady—rotate salty, sweet, or gummy categories with confidence.

You do not always need the one perfect reinforcer. Keep a small bowl of varied, moderately liked edibles at the table. Let the learner sample across trials. If attention dips, swap in a new piece from the same food group instead of pausing for a full preference assessment. This simple rotation can save time and still keep responding strong.