Perceptuaj and Motor Skills, 1978,47,869-870.
@ Perceptual and Motor Skills 1978
LATERALITY PREFERENCE PATTERNS OF LEARNING DISABLED CHILDREN1 NEIL H. SCHWARTZ
RAYMOND S. DEAN University of Wisconsi+Madison
Arizona Stde University
Summary.-This study concerned the prediction of group membership of 40 learning disabled and 40 normal children on the basis of preference for laterality of the children and of their parents. A stepwise discriminant analysis showed maternal and paternal lateral preferences could correctly identify approximately 85% of the cases. Orthogonal contrasts showed that, although children themselves did not differ in the degree of laterality, parents of learning disabled children were significantly more bilateral in their preference patterns than normals. In recent years, there have been many efforts to apply advances in basic research on the lateralization of cerebral function to various syndromes. It seems apparent that the ultimate value of such research on the function of the brain must be assessed by its ability to predict events in naturalistic situations. Various investigators have hypothesized a connection between the individual's degree of lateralization and numerous learning problems. A critical review of research which examines this question may be faulted on two grounds (Dean, i n press a, in press b ) . First, and most importantly, nonintrusive measures employed have had questionable psychometric properties; and secondly, many studies suffer from the view of laterality as being a trichotomy. The present study attempted to ( a ) assess laterality in a continuous manner using the recently published Dean Lateralicy Preference Schedule (Dean, 1978) in an effort to distinguish between groups of normal and learning disabled children and ( b ) to investigate maternal and paternal preference patterns as predictor variables of specific learning disabilities. Method.-Subjects were 8 0 children of both sexes who ranged in chronological age from 9.6 to 12.8 yr. Of the subjects 20 males and 20 females were randomlv selected from a summer program for children with learning disabilities. A group of 40 normal subjects was selected from children attending a summer crafts program based on their goodness of match with children in the learning disabled group on sex, age (k 2 mo.), present grade placement, and socioeconomic status as determined by the occupation of the family's major wage earner. Each child was administered the Dean Laterality Preference Schedule2 (Dean, 1978) which has been shown to measure children's lateral preference for peripheral tasks with a high degree of reliability and predictive validity.' The schedule is a 49-item self-report measure which has been shown to measure lateral preference on activities involving the eyes, ears, hands, legs, and feet. The inventory requires the respondent to indicate on a five-point Likert scale his preference from right always to left always on a number of tasks. A score is derived for each item using ascending weights for each response
'Address requests for reprints to Neil H. Schwartz, 322 Payne Hall, Arizona State University, Tempe, Arizona 85281. "pies of the scale may be obtained from the author upon request. 3R. S. Dean, Reliability and predictive validity of the laterality preference schedule with preadolescents. ( I n submission, 1978)
N. H. SCHWARTL & R. S. DEAN
category: right always = 1, right mostly = 2, both equally often = 3, left mostly = 4, and left always = 5. A general laterality score is formed by multiplying the total number of responses for each category, e.g., right always, by its appropriate weight and summing across response categories. Information regarding maternal and paternal preference was obtained with a shortened version of the schedule incorporated in each child's permission-to-participate slip. In an effort to distinguish between groups in a multivariate fashion, children's scores on the schedule and those of their mothers and fathers were entered into a stepwise discriminant analysis. Results.-Table 1 shows the means and standard deviations for both groups on the full and parental scales. Utilizing children's laterality scores and those of their parents as predictor variables, a stepwise discriminant analysis produced one significant function ( x 2 = 58.36, fi .001). Of the three possible variables, maximum separation .001) and fathers' (R.n between groups was obtained with mothers' (P1.m = 44.19, 9 = 30.27, P .001) laterality scores. Surprisingly, children's laterality scores did not .05) to the function, nor did orthogonal contrasts show groups add significantly ( p to differ significantly in laterality. Without prior knowledge, it was possible to assign 84.74% of the children in the present analysis to their correct group, solely on the .001) bilateral nature of parents of children in the learning basis of the greater ( p disabled group.