VISUAL CLIFF

an apparatus to explore the cultivation of depth perception in non-speaking human babies and animals, specifically, whether depth perception is an inborn capacity or acquired though visuomotor encounters. The apparatus contains a checkerboard table, falling steeply down a "cliff" to another surface that also has the checkerboard look, some distance beneath the tabletop. The apparatus is blanketed with a transparent exterior, and the involved party is placed upon this at the border between the cliff and the table's top. Reluctance to climb onto the exterior covering the cliff is interpreted as an implication that the involved party can determine the obvious difference in depth between the apparatus's two sides. The majority of babies as young as 6 months old won't cross over to the side over the cliff.