Rewards and curiosity
Variable reward
When rewards arrive unpredictably, people repeat the behavior more.
Well supportedSeveral studies or meta-analyses point the same way.
Example
Lotteries, loot boxes, refreshing a feed. Not every try pays off, so you try again.
Why it works
When rewards come after an unpredictable number of actions, a variable-ratio schedule, behavior stays frequent and persists long after rewards stop. It is a classic finding from animal research.
On the web
Put the surprise in what appears, not in how much people get. Keep it to variations nobody loses from: a line in a quiz result, a daily tip, a different completion animation.
When it backfires
Paid chance mechanics can fuel compulsive spending and, in Japan, may fall under premium regulations. Avoid designs where luck sets what people pay or receive.
Sources
Documents how reinforcement schedules shape behavior, including high, persistent response rates under variable-ratio schedules.
Ferster, C. B., & Skinner, B. F. (1957). Schedules of Reinforcement. Appleton-Century-Crofts. Open source