title: No evidence for a correlation between behaviour and the size of the Y chromosome.
abstract: Y chromosome variation has been studied in three groups of Norwegian males: 35 boys from an adolescent psychiatric hospital; 45 men from a hospital for hard-to-manage or dangerous, psychotic men; and 26 boys from two ordinary school classes. Y chromosomes with 1, 2, and 3 brightly fluorescing bands were found in all three groups. One boy carried a Y with no bands. The mean values of the Yf/Yq ratio were not significantly different in the three groups (Yf is the length of the distal, brightly fluorescing part of Yq). Two cases of XY/XYY mosaicism were found among the psychotic men. The study shows that the human species is polymorphic with regard to the size of the Y chromosome, i.e. the number of fluorescent bands in the long arm. No phenotypical manifestation of this polymorphism, particularly as regards behaviour, was found.
mesh_terms: D000293:Adolescent; D000328:Adult; D001519:Behavior; D002648:Child; D002869:Chromosome Aberrations; D014644:Genetic Variation; D006801:Humans; D007621:Karyotyping; D008297:Male; D001523:Mental Disorders / Q000235:genetics; D011618:Psychotic Disorders / Q000235:genetics; D012730:Sex Chromosomes / Q000648:ultrastructure*