ABSTRACT
When young children first begin to move about and explore their environment they seem accident prone. Parents of children at the crawling or toddling ages worry that their children may fall down stairs, off a balcony or off a bed or a chair. The reasons why older children fall less often have been questioned. Does the child fall less as he grows older because he learns to better judge height and depth, or because he gains control over his motor responses, or a combination of both? In 1960 Gibson and Walk described the 'visual cliff, apparatus which enabled them to answer this question without endangering the child. Using this apparatus they determined that most human infants can perceive depth by the time they can crawl. The infants' control over their motor responses, however, is not well developed and it is for this reason that Gibson and Walk suggest that 'infants should not be left close to a brink, no matter how well they may discriminate depth' (p. 64).
