Is depth perception innate or is it learned through experience? The visual cliff experiment sought to answer this question. In the experiment, a table was designed so that a checkered pattern would appear to drop off like a cliff. Infants were placed on this table and coaxed to cross the "deep end" of the table by their mothers to determine whether or not these infants possessed depth perception. And as it turns out, they did. The original conclusion of these experiments was that depth perception was innate, although all these infants had unavoidably already had experience interacting with their environment.
Of course, these experiments took place before ethical concerns were more widely considered. Many of the infants would cry for their mother's help because they were too afraid to cross the "deep end". Regardless, depth perception is now considered to be partially innate, refined through experience.