[Neuroscience] "higher prenatal testosterone in women" and homosexuality

James Michael Howard jmhoward at anthropogeny.com
Sat Jul 29 06:56:16 EST 2006

 Neuropsychobiology. 2006 Jul 26;53(4):210-214 [Epub ahead of print]

Finger Length Ratio (2D:4D) and Dimensions of Sexual Orientation.Kraemer B,
Noll T, Delsignore A, Milos G, Schnyder U, Hepp U. 
Department of Psychiatry, University Hospital, Zurich, Switzerland.

Background: It has been suggested that both adult sexual orientation and
the 2nd to 4th finger length ratio (2D:4D) are influenced by prenatal
testosterone levels. Bearing this in mind, 2D:4D has been tested as a proxy
measure of the putative prenatal testosterone impact on adult human
homosexuality, but the results are inconsistent. To date, most studies in
this field of research comprise categorical group comparison of
heterosexuals and homosexuals with respect to their 2D:4D. Aims: The
purpose of our study was to evaluate 2D:4D and the dimensional perspective
of sexual orientation in addition to categorical results. Methods: We
examined a community-based sample of 409 subjects and calculated
correlations of 2D:4D and sexual orientation as a continuum ranging from
homosexual to heterosexual. Results: We found a significant negative
correlation of 2D:4D with homosexual orientation (fantasy, attraction,
activity and general score) in women, but not in men. Conclusions: Our
results indicate that with higher prenatal testosterone levels in women,
the likelihood of homosexual orientation might increase. We hypothesize a
continuous neurohormonal sexual differentiation of the brain, most notably
for women, that overrides categories and results in varying dimensions of
sexual orientation. This hypothesis contrasts with the predominant
suggestion of fixed organizational effects of androgens in the brain and a
categorical sexual orientation. Copyright (c) 2006 S. Karger AG, Basel.

I invite you to read

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