Right- and left-handedness

Stevenson Smith
1916 Psychological bulletin  
Doll (i) confirms the results of earlier investigations in finding the incidence of left-handedness far greater among the feebleminded than among normal subjects. He says (p. 58): "The feeble-minded of all grades are predominantly left-handed in strength of grip, as is shown by the superiority of the averages for left grip over right and the high correlation existing between them. These results do not show a tendency toward ambidexterity but towards sinistrality at all ages and grades."
more » ... nd grades." Examination of his tables shows the following results: of the 123 girls whose grip was measured 47 per cent, had greater strength in the right hand, 6 per cent, had equal strength in the two hands and 47 per cent, had greater strength in the left hand; of 310 boys there were 51 per cent, with greater right grip, 5 per cent, with equal grip for the two hands, and 44 per cent, with greater left grip. Those with a greater left grip show a greater relative difference between the strength of the two hands than do those with a greater right grip. Nice (5) reports the case history of a left-handed child who, for the first two years of her life, was encouraged to use her right hand. After two years this effort at training was discontinued. She showed delayed speech development with sudden improvement at three years and seven months. The author's opinion that the retarded speech development was caused by training the right hand is not a conclusion necessitated by the results cited. In a readable little book on ambidexterity Macnaughton-Jones (4) reviews some of the experimental results in studies of right-and left-handedness, gives some attention to the neurology of these functions, and deals at length with the advantages of bimanual education. Jones (2) made measures of girth, length and tapping rate for the two arms of right-and left-handed subjects, as well as of those whose handedness had been reversed by training. He reports that bone measurements are diagnostic of born handedness whereas muscle measurements are diagnostic of adopted handedness. The ten thousand cases said to have been measured are not reported in full, only sample cases being given. In rate of tapping the group whose preferred handedness was transferred by education do not
doi:10.1037/h0069995 fatcat:gorlu2nsw5al5hxku2i4w4mfle