The Visual Cliff

1960

Eleanor Jack Gibson (1910–2002)

Is our ability to perceive depth innate, or do we learn it by experience? Does its method of movement influence the way an animal perceives the world? In a series of elegant experiments, psychologist Eleanor J. “Jackie” Gibson laid the groundwork for the contemporary science of perceptual development; she is best known for her study of the visual cliff, published as a popular article in Scientific American in 1960.

With her colleague Richard Walk, she devised an experiment to test whether experience plays a role in depth perception. The near side of the visual cliff was a board painted like a checkerboard, and a flat panel of thick glass was placed on top of it. On the far side of the cliff, a checkerboard floor was placed one foot lower, though the heavy glass continued the entire length, giving it a visual sense of depth, like a cliff.

Gibson and Walk tested whether human infants, as well as the young of several other species, would crawl out onto or cross the visual cliff. The thirty-six human babies tested ranged from six to fourteen months old, all of them crawling. The babies were placed in the center of the board and the mothers called to them from either the “shallow” side or the “deep” side. Most of the babies moved from the center at their mother’s call, but only three moved in the direction of the deep side. Many of the infants peered down on the deep side, even patting the glass, but refused to move out onto it. Gibson and Walk concluded that depth perception emerges about the time that babies learn to crawl. Thus experience probably plays only a minor role in depth perception. Research with other animals confirmed that depth perception is linked to the emergence of mobility.

SEE ALSO Growth Studies (1927)

This photograph shows a baby crawling on top of the “visual cliff,” designed by Eleanor Gibson and Richard Walk at Cornell University in 1960.