Delay discounting of qualitatively different reinforcers in rats.

The team put rats in a chamber with two levers.

Pressing one lever gave a small reward right away.

Pressing the other gave a bigger or better reward after a delay.

The delay grew longer across trials.

The rewards were either normal pellets, sweeter pellets, or sugar water.

The goal was to see if tastier rewards would make rats wait longer.

Rats still switched to the immediate small reward as delays increased.

The hyperbolic curve described their choices.

Surprise: the kind of reward did not change how fast they gave up waiting.

More sugar or bigger piles did not flatten the curve.

Green et al. (2004) ran a near-copy of this task and also saw no effect when they varied pellet amount instead of taste.

Together the two rat studies show that neither amount nor flavor moves the discounting rate.

Holt et al. (2019) later repeated the null result in pigeons, so the missing “magnitude effect” looks real across species.

Bruce et al. (2019) seems to clash: hens worked harder for better feed under fixed-ratio schedules.

The difference is procedure.

Bruce used short immediate reinforcement.

L et al. used long unpredictable delays.

Quality boosts responding when the reward is close; it does not help organisms wait.

If you are building a token board or delay tolerance program, do not count on “better” treats to make kids wait longer.

Use quality to strengthen initial responses, then teach waiting with other tools like priming, fading, or self-management.