What experimental tool is used to study depth perception in infants and animals?

The visual cliff is an experimental tool specifically designed to study depth perception in infants and animals. This apparatus typically consists of a glass surface that creates the illusion of a steep drop-off, allowing researchers to observe whether subjects will crawl or walk across the cliff. The purpose of this experiment is to assess the ability to perceive depth and assess whether the subject has an innate ability to recognize and react to potential dangers.

By placing infants or animals on the shallow side of the visual cliff and observing their willingness to cross to the deep side, researchers can gauge their ripening sense of depth perception and their understanding of the consequences that might emerge from falling. Typically, infants develop this ability over time, indicating a significant development in spatial awareness and cognitive processing.

The other options, while relevant to developmental psychology, do not directly assess depth perception in the same way that the visual cliff does. Theory of mind relates to understanding others' thoughts and beliefs; temperament deals with individual differences in emotional reactivity and self-regulation; and trust and mistrust focus on the early relationships and interactions with caregivers. None of these concepts provides a direct methodological approach to evaluate how infants and animals perceive depth.