Intermodal relationships in children's perception.

Since judgment of geographical slant requires the use of both optical and postural information, such judgments were used to determine whether intermodal relationships affect children's perception. First, third, and fifth graders made judgments of geographical slant of surfaces depicted in photographs either with or without postural inclination. The results indicate the existence of a linear mechanism which compensates for the effect of postural inclination. Compensation was about 50% of that expected from an ideal perceptual system and did not change with age. The present data are similar to those previously reported for adults and suggest that the compensation process develops early in childhood.