Adultsʹ perception of childrenʹs height and reaching capability

This study investigated the influence of some characteristics of the task, the model, and the observer, in the estimation errors of adults while judging childrenʹs affordances. One hundred and eighteen adults, divided in 4 height groups, estimated height and vertical reaching capability of 3 girls (3.55-, 4.74- and 7.06-years old), in the presence and in the absence of the model. Constant errors (CE) (estimation–real value), absolute percent errors (APE) (|1 − estimation/real value| × 100), and error tendency (underestimations, right judgments, or overestimations) were calculated. A model and a condition effect were verified on APE. APE for the younger model were greater than for the other models (p < 0.001), and APE in the absence of the model were greater than in her presence (p < 0.05). Generally, adults underestimated height (51.8% of underestimations vs. 32.3% of overestimations) and overestimated reachability (51.3% of overestimations vs. 37.7% of underestimations). The overestimation of reachability was more notorious for the younger model, which might reflect adultsʹ difficulty to consider the specificity of younger childrenʹs body proportions. Actually, the overestimation bias may suggest that adults perceive young children as on the basis of adultʹs geometrical proportions.