title: The effect of sex, laterality and familial handedness on intellectual abilities.
abstract: This study assessed the relationship of sex, familial handedness and laterality to the intellectual abilities of 116 right-handed 12-14-yr-old subjects. Verbal scores were predicted by an interaction between familial handedness and the subject's own laterality. A strong right ear advantage for verbal stimuli and a large lateral difference between the ear advantage for verbal and nonverbal stimuli predicted high Verbal Intelligence scores for the strong right hand-eye preference subjects with family histories of dextrality. Conversely, attenuated ear advantage scores for verbal stimuli predicted high Verbal Intelligence scores for the strong right hand-eye familial sinistral subjects. Although the results were less consistent for Performance Intelligence scores, they were significantly and positively related to assessed hand-eye preference, and a significant interaction between familial handedness and the subject's own laterality was observed for the Object Assembly subtest. A strong left ear advantage for nonverbal stimuli predicted high scores for the strong right-preference familial dextral subjects and attenuated ear advantage for nonverbal stimuli predicted high scores for the strong right-preference familial sinistral subjects.
mesh_terms: D000293:Adolescent; D001307:Auditory Perception / Q000502:physiology; D002648:Child; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D005823:Genetics; D006801:Humans; D007360:Intelligence; D008297:Male; D012737:Sex Factors; D014888:Wechsler Scales