In a paper to be published soon in Evolution and Human Behavior, they suggest the advantage accrues not to relatives of the opposite sex, but to those of the same one. They think that genes which cause men to be more feminine in appearance, outlook and behaviour and those that make women more masculine in those attributes, confer reproductive advantages as long as they do not push the individual possessing them all the way to homosexuality…
There are also data which suggest that having a more feminine personality might indeed give a heterosexual male an advantage. Though women prefer traditionally macho men at the time in their menstrual cycles when they are most fertile, at other times they are more attracted to those with feminine traits such as tenderness, considerateness and kindness, as well as those with feminised faces. The explanation usually advanced for this is that macho men will provide the sperm needed to make sexy sons, but the more feminised phenotype makes a better carer and providerin other words an ideal husband. And, despite all the adultery and cuckoldry that goes on in the world, it is the husband who fathers most of the children.
As far as masculinised women are concerned, less research has been done on the advantages that their appearance and behaviour might bring. What data there are, however, suggest they tend to have more sexual partners than highly feminised women do. That may, Dr Zietsch speculates, reflect increased competitiveness or a willingness to engage in unrestrained sexual relations (ie, to behave in a male-like way) that other women do not share.
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