A behavioral analysis of incentive prompts for motivating seat belt use.

The team watched drivers enter a factory parking lot. They noted who wore seat belts.

Next they held a daily raffle. Only workers who buckled up could enter. They compared this to a free raffle open to everyone.

The study flipped the raffle rules on and off four times to be sure any change was real.

When the raffle required a seat belt, use jumped from 26% to 46%. When the raffle opened to all drivers, use stayed flat.

After the team removed the raffle, some drivers still buckled up, but the gain shrank.

Glenn (1983) ran the same raffle the next year and got the same jump, showing the effect holds up.

Haring et al. (1988) swapped the raffle for a free soft-drink coupon and still doubled belt use. All three studies say the same thing: the prize must depend on the target behavior.

Van Houten et al. (2011) pushed the idea further. They wired the gas pedal so it stayed stiff until the belt clicked. Every commercial driver then wore the belt 100% of the time. The early raffle proved the principle; the pedal made it automatic.

Dagnan et al. (2005) looks like a contradiction. They used only a posted sign at senior villages and kept a 25-point gain for four years without prizes. The difference is age and setting. Older adults respond to polite prompts; factory workers needed a tangible reward.

If you want staff, clients, or parents to adopt a habit, tie a small perk to the act and deliver it right away. A raffle entry, coupon, or token works. Once the behavior is steady, fade the prize slowly or switch to a built-in cue like a pedal delay to keep the gain alive.