Pressure (caused by a failure of men).
This argument was advanced most explicitly by Anthropologist Elizabeth Cashdan of the University of Utah in a recent paper (link is external) in Current Anthropology that is ostensibly concerned with changing female body shape. Cashdan believes that the optimal female body shape is not the hourglass figure of a Marilyn Munroe or a Scarlett Johansson with narrow waist and large breasts. In most societies, women actually have wider waists and such figures are more attractive to men in subsistence societies, such as the Zulu (pictured) where food is scarce and also in countries like Denmark and Britain where there is greater equality between men and women.
Youth (less developed breasts) and oestrogen (broader pelvis, disproportionately). The hourglass’ sole advantage is seeing that a woman probably isn’t pregnant, it’s her relative lower risk of fertility to a pelvic-heavy pear shape.
In societies where women are under pressure to provide for their children, increased testosterone production increases their stamina, strength, and competitiveness. However, along with stress hormones, testosterone also increases the amount of fat stored about the waist, thereby reducing stereotypical femininity of the figure.
Cortisol fat. It’s called cortisol fat.
… When they compete with each other for jobs, they are more interested in seeming competent than in looking sexy….
The only reason women act like men, is because men dropped the ball. Men failed us. We’re picking up the slack, even in the economy (who wants to be a wage slave, seriously?).
Such a neat match between body and behavior (or phenotype) and what is required for competitive success is really an adaptation.
It’s a circular process. Men become more feminine (xeno-estrogens?) and women respond, which allows men to fall further and further, lower and lower until we get to Pajama Boy.
One thing is certain, if/when women go back to our former ways, the guys don’t get to complain when we act like women either (aka not drinking or sleeping around with them). Expecting us to act like men whatsoever in the first place was ridiculous.