title: Second to fourth digit ratio and numerical competence in children.
abstract: The ratio between the 2nd and 4th fingers (2D:4D)-a potential proxy for prenatal testosterone (T) exposure-shows a sex difference, with males usually having lower mean values; the latter potentially indicates higher prenatal T exposure. We studied relations between 2D:4D and competencies in the domains of counting, number knowledge, and visual-number representation in 73 children aged 6-11 years. Significant negative correlations between numerical performance in all of these areas and right and left hand 2D:4D ratios were found for boys but not girls. To the extent that 2D:4D ratios reflects prenatal exposure to T, the implications are (i) high prenatal T may be associated with better performance on some basic numerical measures for boys, and (ii) prenatal exposure to T may affect boys and girls differently with respect to some numerical competencies.
authors.affiliation: Department for Sociobiology/Anthropology, University of Goettingen, Goettingen, Germany. bernhard.fink@ieee.org
authors.forename: Bernhard
authors.initials: B
authors.lastname: Fink
authors.forename: Helen
authors.initials: H
authors.lastname: Brookes
authors.forename: Nick
authors.initials: N
authors.lastname: Neave
authors.forename: John T
authors.initials: JT
authors.lastname: Manning
authors.forename: David C
authors.initials: DC
authors.lastname: Geary
mesh_terms: D000124:Achievement; D002648:Child; D003071:Cognition; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008433:Mathematics; D011247:Pregnancy; D013739:Testosterone / Q000502:physiology*; D013997:Time Factors
chemical_list: D013739:Testosterone