Effect of Two Warning Signs on Adult Supervision and Risky Activities by Children in Grocery Shopping Carts

398 children, 1 to 6 years of age, and the adults accompanying them in two supermarkets were exposed to one of four treatments. Two experimental treatments featured variations on a warning sign, prompting adults to prevent their children from standing while in the cart seat and basket portions of shopping carts. The two control treatments exposed the adults to advertisements rather than warning signs. No effect was observed of either warning on standing while in cart seats, standing while in baskets, climbing on carts, or standing on the ends or sides of carts; nor was any effect noted on three measures of adult supervision. This lack of effect is attributed to adults' perceptions of the low risk of serious injury to children in carts, their familiarity with carts, the costliness of ensuring compliance with the warnings, and the lack of natural contingencies supporting the prompts. Risky activities by children were related to the child's location in the cart, child's sex, and adult supervision.