The ground is dominant in infants' perception of relative distance.

When making relative distance judgments, adults attend to information provided by the ground surface and generally ignore information provided by ceiling surfaces. In the present study, we asked whether this ground dominance effect is present in infancy. Groups of 5- and 7-month-old infants viewed a display depicting textured ground and ceiling surfaces. Two toys, which were attached to vertical rods, were affixed to the display. The toys/rods were positioned so that one toy was specified as being nearer by the ground surface but farther away by the ceiling surface, while the other toy was specified as being farther away by the ground surface but nearer by the ceiling surface. Under monocular viewing conditions, the infants in both age groups reached preferentially for the toy that was specified as being nearer by the ground surface. This effect was significantly stronger than that observed under binocular viewing conditions. The findings indicate that the infants responded to the distance information provided by the ground surface to a greater extent than to information provided by the ceiling.