The question whether initiating treatment of cerebral palsy in infancy gives better results than therapy initiated later in childhood has been raised and is being debated. It is unlikely that a double-blind study can be arranged to settle this controversy. Experiences gained from management of congenital amputees, observations of copying behavior of small infants, and the relative ease of requiring other motor skills in very young normal children suggest that critical ages influence the quality of motor performances. The acquisition of accent in learning one's first or second language also depends in age of learning and copying that language. These observations strongly suggest the hypothesis that early sensory input affects motor programming also in children with cerebral palsy.