Genetic analysis of orgasmic function in twins and siblings does not support the by-product theory of female orgasm

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Zietsch BP, Santtila P
Publisher: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
Publication year: 2011
Journal: Animal Behaviour
Journal acronym: ANIM BEHAV
Volume number: 82
Issue number: 5
Start page: 1097
End page: 1101
Number of pages: 5
ISSN: 0003-3472


Abstract

The evolutionary basis of human female orgasm has been subject to furious scientific debate, which has recently intensified. Many adaptive explanations have been proposed, invoking functions from pair bonding and mate selection to sucking up sperm, but these have been attacked as being based on flawed logic and/or evidence. The popular alternative theory is that female orgasm is not adaptive and is only evolutionarily maintained as a by-product of ongoing selection on the male orgasm-ejaculation system. This theory has not been adequately tested. We tested one of its central tenets: that selection pressure on the male orgasm is partially transmitted to the female via a positive cross-sex correlation in orgasmic function (susceptibility to orgasm in response to sexual stimulation). Using questionnaire data from over 10 000 Finnish twins and siblings, we found significant genetic variation in both male and female orgasmic function, but no significant correlation between opposite-sex twins and siblings. This suggests that different genetic factors underlie male and female orgasmic function and that selection pressures on male orgasmic function do not act substantively on female orgasmic function. These results challenge the by-product theory of female orgasm. (C) 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.


Keywords

adaptation, evolution, fertility, fitness, heritability, male nipple hypothesis, mate choice, pair bonding, spandrel, upsuck

Last updated on 2019-14-12 at 03:10