J. Lewin et al., HANDEDNESS IN MENTAL HANDICAP - INVESTIGATION INTO POPULATIONS OF DOWNS-SYNDROME, EPILEPSY AND AUTISM, British Journal of Psychiatry, 163, 1993, pp. 674-676
The handedness in three randomly sampled groups of people with learnin
g disabilities consisting of patients with Down's syndrome, epilepsy,
and autism were studied using a validated instrument. All subjects wer
e controlled for neurological and other medical disorders. A statistic
ally significant increase in left-handedness and ambiguous handedness
compared with the general population was found in all groups. There wa
s no significant difference in the rate of left-handedness between the
three groups.