Late Emergence of the First Possession Heuristic: Evidence From a Small-Scale Culture.

Western preschool children often assign ownership based on first possession and some theorists have proposed that this judgment might be an early emerging, innate bias. Five- to 9-year-olds (n = 112) from a small-scale group in Kenya (Kikuyu) watched videotaped interactions of two women passing an object. The object's starting position and the women's gestures were varied. Use of the first possession heuristic increased with age, and 8- to 9-year-olds performed similarly to German 5-year-olds (n = 24). Starting position and gestures had no effect. A control study confirmed that 5-year-old Kikuyus (n = 20) understood the video material. The findings reveal that the first possession heuristic follows different developmental trajectories cross-culturally and stress the role of children's sociocultural environment.