Motor Development and Intellectual Functioning: An Exploratory Study


Delacato 2 , Kephart 7 , and others, have hypothesized that a child must go through particular motor stages during his development if he is to possess certain qualities of adult thought. If a stage (or part of a stage) is omitted, or a child is unable to perform certain movements, his ability to generalize at a higher intellectual level will be adversely affected. This developmental postulate has been applied to normal, mentally subnormal, learning-disordered, and braindamaged children.

The present study was designed to explore this hypothesis with congenital amputees who lack the ability to progress through the conventional developmental sequence. Past investigators 4,5,10 have concluded that congenital amputees, in general, may possess average or above-average intellect. A correlational analysis of severe congenital limb deficiency, which directly influences motor development and intelligence, has not been reported.

The sample consisted of five males and three females with congenital limb deficiencies who were outpatients of the Child Amputee Prosthetics Project in Los Angeles. These children were all from Southern California and the states of Nevada and Arizona. The group encompassed all available cases between the ages of seven and sixteen years (average being 11.33 years) in the CAPP files whose physical anomalies included severe bilateral upper-limb involvement. The deficiencies ranged from bilateral below elbow to bilateral amelia of the upper limbs, with numerous lower-limb involvements. These parameters were established in order to select children whose upper-limb functioning was minimal. The etiology of the limb deficiencies was reported as unknown. Supplementary information regarding ethnic background and socioeconomic status was collected because of their reported influence upon the results of psycho-educational tests.*

The verbal sections of the Wechsler Intelligence Scale for Children (WISC) 11 were administered to the subjects. The performance section of the Wechsler Scale was eliminated because of the inability of these children to manipulate the blocks or puzzle parts. In addition to the psychometric evaluation of intellectual functioning, a cognitive approach was utilized. The subjects were also administered a battery of Piagetian tasks: Conservation of Substance, Conservation of Classes, Numbering, Movement and Velocity, and Spatial Orientation 8,9 . The concepts on which these tasks are based are assimilated approximately between the ages of two and twelve years.

Both from the psychometric and cognitive appraisal of intelligence the correlations between degree of limb deficiency (lower-limb involvement vs no lower-limb involvement) were not significant. The IQ range on the WISC was 87 to 134, the mean and standard deviation being 106.00 and 18.74, respectively. Correlation coefficients were significant at the .01 level between IQ and (1) ethnic background, and (2) socioeconomic status, as would be expected in a general population 1 . Those subjects whose family income was in the lowest category and/or who were members of a minority ethnic group obtained the lower IQ scores.

The findings support earlier investigators who reported that congenital amputees may possess normal intelligence or higher. Gouin-Decarie5 reported the mean IQ of her thalidomide-induced congenital amputees was within the average range (94.4), although a high percentage of the subjects fell below the normal limits. Gingras et al. 4 reported a mean IQ of a congenital amputee sample as also within the normal range 10 .

These exploratory results did not confirm a significant correlation between the degree of limb deficiency, which influences the degree of motor functioning, and the level of intellectual functioning as would be expected. This finding confirms the conclusion, at least dealing with intellectual functioning, presented by Gouin-Decarie 6 , that

.... the severity of the child's handicap does not seem to have been the most significant factor in his development.

While further research is needed, it is proposed that severely involved congenital amputees may in fact progress through the sequence of motor abilities as proposed by certain developmental theorists 7,9 but not in the conventional manner (i.e., prehensile grasping with head and shoulder, or by use of the toes instead of with the hands). Further, the early school enrollment (three years of age) of all subjects may be an important consideration in compensating for the motor deficiency, while other sensory modalities, particularly the teleceptors, may be developed at an earlier age.

These data are not consistent with theories which emphasize an invariate sequence of motor development as a prerequisite for higher intellectual functioning and point to a need for a closer experimental scrutiny of certain assumptions about motor development and intelligence.

Motor Performance Specialist Manhattan Beach City School District, Manhattan Beach, California

1. Burnes, K., Patterns of WISC scores for children of two socioeconomic classes and race Child Development, 41:2:493-499, 1970.
2. Delacato, D. (ed), Neurological organization and reading problems. Charles C Thomas, Springfield, 111., 1966.
3. Flavell, J. H., The developmental psychology of Jean Piaget. D Van Nostrand Co., Inc., New York, 1963.
4. Gingras, G., M. Mongeau, P. Moreault, M. Dupuis, B Herbert, and C. Corriveau, Congenital anomalies of the limbs: part II, psychological and educational aspects. Canad. Med. Assoc J , 91:3:115-119, July 18, 1964
5. Gouin-Decarie, T , A study of the mental and emotional development of the thalidomide children and of the psychological reactions of their mothers. Inter-Clin. Inform. Bull., 6:4:8-12, January 1967.
Motor Development and Intellectual Functioning
6- Gouin-Decarie, T., The thalidomide project: Five years of research Inter-Clin. Inform. Bull., 9:12:1-4, September 1970.
7 Kephart, N., The slow-learner in the classroom. Charles E. Merrill Publishing Co., Columbus, Ohio, 1971.
8 Kershner, J. R., Children's conservation of multiple space relations: effects of perception and representation J. Learning Disabilities, 4:6:31-36, 1971.
9 Phillips, J. L , The origins of intellect: Piaget's theory W. H. Freeman and Co., San Francisco, 1969
10. Robinson, M., and L Tatnall, Intellectual functioning of children with congenital amputation, clinical proceedings Children's Hospital of the District of Columbia, 24:4:100 107, 1968.
11. Wechsler, D., Wechsler Intelligence Scale for Children. Psychological Corp., New York, 1949
Descriptors: Motor development; intelligence, congenital limb deficiencies