That doesn't mean that it is time to take the gates off of your stairs just yet. Keep things childproofed until your child is older. Remember that gates should be installed on both the top and bottom of every staircase in your home. For how long? Probably at least until your child is able to open them on his own.
Sources:
Functional developmental evaluation. Prerequisite to habilitation. Capute AJ - Pediatr Clin North Am - 01-FEB-1973; 20(1): 3-26
Linguistic and auditory milestones during the first two years of life: a language inventory for the practitioner. Capute AJ - Clin Pediatr (Phila) - 01-NOV-1978; 17(11): 847-53
Clinical linguistic and auditory milestone scale: prediction of cognition in infancy. Capute AJ - Dev Med Child Neurol - 01-DEC-1986; 28(6): 762-71
The Denver Developmental Assessment (Denver II)

