Delay discounting by pathological gamblers.

Clarke et al. (2003) asked two groups to pick between smaller money now or larger money later. One group had pathological gamblers. The other group had adults who did not gamble.

The choices were fake, but the amounts felt real. People chose between, say, $100 today or $1,000 in one year. Delays ranged from one week to ten years.

Gamblers took the quick, smaller payoff far more often. Their delay discounting curve was much steeper than the control curve.

In plain words, gamblers acted as if future money was worth a lot less.

Odum et al. (2020) reviewed dozens of studies and found the same pattern: people with addictions discount money more steeply. The 2003 gambler data sit right inside that bigger picture.

Macaskill et al. (2023) show one reason the curve can steepen: when people have nothing else to do while they wait, the delayed reward feels even smaller. That lab trick may partly explain the gambler results—casinos remove clocks and other reinforcers.

Au-Yeung et al. (2015) add another layer: smaller rewards are discounted more than larger ones. Because the 2003 study used a fixed $1,000 top prize, future work could test whether giving gamblers choices with much larger stakes flattens their curve.

You can spot impulsive choice in clients by using the same five-minute hypothetical money task. If the curve is steep, teach delay tolerance by adding competing reinforcers during wait times and by magnifying the delayed payoff. These tweaks come straight from later lab work and cost nothing to try.