The acquisition of basic self-help skills, that is, toileting, bathing, toothbrushing and others has important meaning not only to relieve instructors from their work load, but also to free severely mentally retarded persons from restrictions in their activities. And the acquisition of such skills is not independent of their life, deficiency and development.
We tried to examin the relation between some kinds of such skills and cognitive development．
20 subjects are institutionalized and the mean chronological age of them is 31years, 8 months.
Results indicate that many self-help skills tasks require 2 years of developmental age at least in cognitive area to be performed in response to verbal command and self-direction.
Members who often wet their pants show a tendency to find difficulty in performing the task to put a circular boad into the hole which has been rotated in a 180-degree arc from the first position.