Original archive video of Gibson and Walk’s Visual Cliff experiment: testing infant depth perception by getting them to walk over glass plates suspended above a drop.
The researchers wanted to find out whether 6 to 14 month-old infants could perceive depth.
The study put the infants, one at a time, in the middle of a table, with one side replaced by glass so you could see the ‘drop’.
Their mothers would try and tempt them over both sides, and if the kids had no depth perception, the glass ‘drop’ wouldn’t seem scary and they’d just walk straight over. Those who could see the ‘drop’ would avoid it.
Pretty much none of the infants wanted to walk across the ‘visual cliff’, suggesting that even kids of 6 months old could perceive depth.
But what of infants younger than this? When does depth perception develop?
In 1973, a study by psychologist Andrew Schwartz placed five and nine-month olds on each side of the ‘visual cliff’ and measured their heart rate.
When placed over the glass ‘drop’, the five month olds typically showed no increase in heart rate, suggesting there was no danger response. This suggests depth perception probably kicks in between about five and six months old.
via Mind Hacks