title: A retrospective study of the relationship between birth history and handedness at six years.
abstract: Bakan's hypothesis that sinistrality is caused by perinatal insult was investigated by attempting to relate the handedness of 1094 six-year-old children to many aspects of their birth history ascertained from hospital records. Handedness of the children and their families was obtained by questionnaire. A secular increase in the frequency of sinistrality was noted, from 6.2% among grandparents to 17.5% among the children. Most boys were left-handed than girls. Only two aspects of birth history predisposed to sinistrality: boys born by breech delivery and children born to primiparous mothers over 38 years old were more likely to be left-handed.
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D007744:Obstetric Labor Complications / Q000209:etiology*; D010375:Pedigree; D011247:Pregnancy