Characteristics of Handedness in Japanese Adults: Influence of Left-handed Relatives and Forced Conversion

A handedness scale consisting of 13 questionnaire items selected from those of D. Raczkowski, J. W. Kalat, and R. Nebes (1974, Neuropsychologia, 12, 43-47) was found to have high internal consistency for both males and females (coefficient alpha = .96 for both sexes), high test-retest reliability (r = .97 for males and .96 for females), and a correlation of .83 with a behavioral measure of handedness. Males exhibited more nonfamilial, but not familial, left-handedness than did females. Self-description as strongly right-handed or as strongly left-handed predicted questionnaire handedness categorization better than did hand used for writing.