Crawling-onset age predicts visual cliff avoidance in infants.
Two experiments are reported that tested the effects of crawling-onset age, the amount of crawling experience, and testing age on avoidance of the deep side of a visual cliff apparatus by human infants. In Experiment 1, 49 infants ranging in age from 7 to 13 mo. were tested on the visual cliff after 1 or 2 mo. of crawling experience. Discriminant analysis revealed that crawling-onset age, and not crawling experience, discriminated between those infants who crossed and those infants who avoided the apparent drop-off. Infants who crossed the deep side were infants with an early crawling-onset age. In Experiment 2, 40 infants were tested on a visual cliff apparatus, half at 9 and half at 12 mo. of age. Discriminant analysis again found that crawling-onset age discriminated between infants who crossed the infants who would not cross the deep side, whereas testing age alone did not. These results call into question the idea that experience crawling is critical in inducing visually guided avoidance behavior in infants. It is argued  that the crawling-onset age effect occurs because crawling during the tactile phase of infancy interferes with later visual control of locomotion.
D000367:Age Factors; D001362:Avoidance Learning; D003867:Depth Perception; D005260:Female; D006801:Humans; D008297:Male; D009048:Motor Skills; D002666:Psychology, Child