title: The ratio of 2nd to 4th digit length: a proxy for testosterone, and susceptibility to HIV and AIDS?
abstract: The incidence of HIV and AIDS is high in sub-Saharan Africa and in male homosexuals. It is suggested that testosterone-mediated immune dysfunction may account for this pattern. The ratio of the length of the 2nd and 4th digit (2D:4D) is negatively related to prenatal and adult testosterone concentrations. There is evidence that black South Africans have lower 2D:4D ratios than most other populations and male homosexuals have lower 2D:4D ratios than male heterosexuals. Men with low 2D:4D ratios may also be more sexually active and/or more fertile than men with high ratio. We suggest that men and women with low 2D:4D are susceptible to HIV infection and AIDS and babies with low 2D:4D ratio susceptible to vertical transmission. Infection rates may therefore be reduced by education and condom supply directed towards low 2D:4D adults.
authors.affiliation: School of Biological Sciences, University of Liverpool, UK. jtmann@liv.ac.uk
authors.forename: J T
authors.initials: JT
authors.lastname: Manning
authors.forename: P
authors.initials: P
authors.lastname: Henzi
authors.forename: P E
authors.initials: PE
authors.lastname: Bundred
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000209:etiology*; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D015658:HIV Infections / Q000209:etiology*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008954:Models, Biological; D012307:Risk Factors; D013739:Testosterone / Q000378:metabolism*
chemical_list: D013739:Testosterone