title: Salivary testosterone levels are unrelated to handedness or cerebral lateralization for language.
abstract: Behavioural and cerebral lateralization are thought to be controlled, at least in part, by prenatal testosterone (T) levels, explaining why sex differences are found in both laterality traits. The present study investigated hormonal effects on laterality using adult salivary T levels, to explore the adequacy of competing theories: the Geschwind, Behan and Galaburda, the callosal, and the sexual differentiation hypotheses. Sixty participants (15 right-handers and 15 left-handers of each sex) participated. Behavioural lateralization was studied by means of hand preference tests (i.e., the Edinburgh Handedness Inventory and the Quantification of Hand Preference test) and a hand skill test (i.e., the Peg-Moving test) whereas cerebral lateralization for language was studied using the Consonant-Vowel Dichotic Listening test and the Visual Half-Field Lexical Decision test. Salivary T and cortisol (C) concentrations were measured by luminescence immunoassay. Canonical correlations did not reveal significant relationships between T levels and measures of hand preference, hand skill, or language laterality. Thus, our findings add to the growing literature showing no relationship between T concentrations with behavioural or cerebral lateralization. It is claimed that prenatal T is not a major determinant of individual variability in either behavioural or cerebral lateralization.
authors.affiliation: a Research Centre for Psychophysiology and Education , National and Kapodistrian University of Athens , Athens , Greece.|b Department of Experimental Psychology , University of Oxford , Oxford , UK.
authors.forename: Marietta
authors.initials: M
authors.lastname: Papadatou-Pastou
authors.affiliation: b Department of Experimental Psychology , University of Oxford , Oxford , UK.
authors.forename: Maryanne
authors.initials: M
authors.lastname: Martin
authors.affiliation: c Institute of Psychology , University of Lausanne , Lausanne , Switzerland.
authors.forename: Christine
authors.initials: C
authors.lastname: Mohr
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D007118:Immunoassay; D007802:Language; D008163:Luminescent Measurements; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D011581:Psychological Tests; D012463:Saliva / Q000737:chemistry*; D012727:Sex Characteristics; D013739:Testosterone / Q000378:metabolism*; D055815:Young Adult
chemical_list: D013739:Testosterone; D006854:Hydrocortisone
keywords: Hand preference; cerebral laterality; dichotic listening; hand skill; visual half-field