Effects of increased response effort and reinforcer delay on choice and aberrant behavior.

The team ran a forced-choice preference test. They asked clients to pick between two reinforcers.

They then made one option harder to get or made the client wait longer for it.

The goal was to see if effort or delay would kill the item’s power to reward.

Hard work did not ruin the reward. Clients still picked the high-effort item they liked.

Long waits were different. When the delay grew, choices flipped and became messy.

Problem behavior rose in both cases, but delay made it jump higher.

Kim et al. (2025) looked at 38 choice studies. They say effort and delay both shift with each client’s history. The new data match that view.

Steege et al. (1989) showed humans chase the fastest payoff. Walley et al. (2005) add the twist: effort alone won’t scare them off, but delay will.

Kydd et al. (1982) found pigeons ignored immediacy when total delay stayed equal. The human data now show we do care about immediacy, pointing to a species gap.

Keep reinforcers quick. If you must add steps, keep the wait short or insert a bridge. Watch for spikes in problem behavior any time the road to reward gets longer.