title: The effect of explicit cultural bias on lateral preferences in Tunisia.
abstract: Hand, eye and foot preferences in Tunisia were examined in relation to age, gender and geographic location. We analyzed 1291 questionnaires from 653 men and 638 women, aged 8 to 74 years. Despite the cultural pressure against the use of the left hand for food-related activities, the overall frequency of left-hand writers (10.9%) was comparable to that found in the Western world. The frequency of left-hand writers was higher for subjects with one left-handed parent, and even higher for subjects with two left-handed parents than for subjects whose parents were right handed. The frequency of left-hand writers dropped to 5.9% in the older age-group; it was found to be higher in Tunis, the largest and most Occidental city, than in other cities, while left-hand eating was lower in the South than in the Center or in the North. The frequency of left-footers also dropped in the older age groups and was higher in Tunis than in other cities. Eye preference, consistency of preferred-hand use, crossed hand-eye laterality, crossed hand-foot laterality and gender-related differences in lateral preferences were all comparable to Western results. These data suggest that lateral preferences are partly influenced by a genetic factor, but that handedness (and to a lesser degree footedness) emerges from the intricate interaction of several factors including genetic and cultural influences.
authors.affiliation: Laboratoire Cognition et Dévelopment, CNRS, Boulogne, France. dahmen@psycho.univ-paris5.fr
authors.forename: Riadh
authors.initials: R
authors.lastname: Dahmen
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Fagard
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D003469:Culture; D003625:Data Collection; D005260:Female; D005528:Foot / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology*; D005843:Geography; D006225:Hand / Q000502:physiology; D006236:Handwriting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009799:Ocular Physiological Phenomena; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014416:Tunisia / Q000453:epidemiology; D014505:Urban Population