On the possibility of advancing and retarding the motor development of infants.

Abstract

The author proposes the theory that infants who are superior to the average child in some one respect, as superior strength, will not be advanced in motor development, but that infants suffering from a corresponding deficiency may be retarded. The discussion is orientated primarily toward walking. Three postulates are formulated: (1) there are multiple requirements for the onset of walking, (2) these requirements are not met simultaneously, and (3) these factors are to some degree independent in their development. The deductions are made that the onset of walking (1) can be delayed by postponing the fulfillment of any single factor beyond date of normal walking, and (2) can be induced at a specific date earlier than normal only if all factors involved are moved forward to this date. Ossification and strength, intelligence, sensory handicaps, special practice, and restriction of practice are discussed in relation to the onset of walking.

Potential Value of Four Early Developmental Milestones in Screening Children for Increased Risk of Later Retardation

“…Abt et al (1929) correlated the IQ with the historical age for walking and talking in 1, OOO children referred to a psychiatric clinic (IQ range 10-159; mean 80 for boys and 82 for girls). The fact that their correlation coefficients were as high as r = 0.,3-0.4 was shown by Dennis (1943) to be entirely accounted for by the results in children with an IQ of less than 70.…”

Hypotonia in the Blind Child

“…The environment has a profound effect on the child's development and personality. Practise and exercise do not hasten the appearance of early motor skills which are determined by maturation (Dennis 1943), although lack of opportunity can cause retarded development, as is often seen in deprived children. At an early age, sighted infants acquire skills largely through incidental learning and most often through visual stimuli.…”

Mental Maturity from Birth to Preadolescence

“…As one result of an attempt to verify his hypothesis that walking is a result of multiple conditions each of which must be present before the ability develops, Dennis (20) found, contrary to general opinion and some researchers, that gifted children walk no earlier than do those of normal ability. Boas (7), however, indicated that among children in the Lincoln School (Columbia) those who are advanced for their age physically are advanced mentally.…”