Children's Estimates of Vehicle Approach Times

Eighty subjects in four age groups (5-6. 7-8, 9-10. adult) viewed a series of movie film clips of a vehicle approaching them along a roadway. Subjects estimated the time at which the vehicle would have passed them. With mean data. all age groups underestimated the time to arrival. with the underestimation decreasing with increasing age. The ability of subjects to scale time was strongly age dependent; the exponent in a Stevens power law relationship increased with age, as did the explained variance, Using r 2 = 0.5 as a criterion for the achievement of time scaling, the percentages in each age group reaching the criterion were 26, 48, 68. and 86 for the 5-6, 7-8, 9-10. and adult groups. respectively. The data suggest that children would reach adult performance at about 12 years of age.