title: Intelligence and salivary testosterone levels in prepubertal children.
abstract: BACKGROUND
  Hormones are one of the regulatory systems influencing brain-cognition interactions and subsequent emotions and behavior in humans and animals. Sex hormones have been found to influence brain structures prenatally, so as to prepare targeted neuronal circuits for activation during and after puberty. Testosterone is believed to affect cognition and thinking in humans as well as between-sex differences in cognitive abilities.
  
  
  OBJECTIVE
  The aim of this paper was to investigate associations between testosterone and different levels of intelligence in young prepubertal children of both sexes.
  
  
  METHODS
  Two hundred and eighty four prepubertal children of both sexes between 6 and 9 years of age provided saliva samples. Of these, 107 were intellectually gifted (IQ above 130), 100 children of average intelligence--randomly chosen from general population (IQ between 70 and 130), and 77 children mentally challenged (IQ less than 70).
  
  
  RESULTS
  Our results have revealed the differences in salivary testosterone levels in boys grouped according to IQ, intellectually gifted and mentally challenged boys having lower salivary testosterone levels than their peers characterized by average intelligence proposing the common biological characteristic of minority IQ groups on both ends of the Gauss curve. In girls, no differences in salivary testosterone levels were found among IQ groups.
  
  
  CONCLUSIONS
  Our findings are the first that present the relationship between testosterone and the broad range of general IQ in childhood. The boys of average intelligence had significantly higher testosterone levels than both mentally challenged and intellectually gifted boys, with the latter two groups showing no significant difference between each other. The functional implications of the brain-cognition interactions remain to be fully explored with regard to the internal milieu influencing neural substrate.
authors.affiliation: Institute of Physiology, School of Medicine, Comenius University, Bratislava, Slovak Republic.
authors.forename: Daniela
authors.initials: D
authors.lastname: Ostatníková
authors.forename: Peter
authors.initials: P
authors.lastname: Celec
authors.forename: Zdenĕk
authors.initials: Z
authors.lastname: Putz
authors.forename: Július
authors.initials: J
authors.lastname: Hodosy
authors.forename: Filip
authors.initials: F
authors.lastname: Schmidt
authors.forename: Jolana
authors.initials: J
authors.lastname: Laznibatová
authors.forename: Matús
authors.initials: M
authors.lastname: Kúdela
mesh_terms: D000704:Analysis of Variance; D002648:Child; D005260:Female; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D011863:Radioimmunoassay / Q000379:methods; D012044:Regression Analysis; D012463:Saliva / Q000378:metabolism*; D012737:Sex Factors; D013739:Testosterone / Q000378:metabolism*
chemical_list: D013739:Testosterone