Contrasting effects of reinforcer rate and magnitude on differential resistance to change in humans

Costa et al. (2025) ran three lab tests with adult humans. They asked: Does bigger reward size or faster reward rate make behavior stick better?

Each person worked on two schedules. One schedule gave lots of small rewards. The other gave fewer but larger rewards. The team then added a TV show to pull attention away. They counted how long each person kept working.

Reward size made no difference. People stayed on task just as long whether the prize was big or small.

Reward speed mattered. When the rich schedule paid off fast, people kept working longer under the TV distraction.

Buskist et al. (1988) once showed that linking bigger prizes to higher response rates boosts how fast people respond. Costa’s team now shows that size does not help behavior persist when life throws in a distraction. The two findings live side by side: magnitude can shape rate, but it does not build staying power.

Duker et al. (1996) found that visual cues paired with rewards make pigeons’ behavior tougher to disrupt. Costa et al. move the same idea to humans and swap cues for rate. Both studies say the same thing: richer conditions create stronger momentum.

Joyce et al. (1988) showed that lower overall reward rates make people less sensitive to choice ratios. Costa adds that higher rates also armor behavior against outside noise. Together they map how rate controls both choice and persistence.

When you need a client to stick with a task despite distractions, schedule the richer reward rate, not bigger prizes. Thin the rate only when you can guard against disruption. This keeps hard-earned skills alive in the real world.