Full Idea
The young girl acquires many subject habits of feminine body comportment - walking, tilting her head, standing and sitting like a girl, and so on ….The more a girl assumes her status as feminine, the more she takes herself to be fragile and immobile.
Gist of Idea
As a young girl assumes her status as feminine, she acts in a more fragile immobile way
Source
Iris Marion Young (On Female Body Experience [2005], p.43), quoted by Kevin Aho - Existentialism: an introduction 3 'Aspects'
Book Reference
Aho,Kevin: 'Existentialism: an introduction' [Polity 2014], p.45
A Reaction
This strikes me as true of young women, but it largely wears off as they get older, at least among modern women. A whole book could be written about women and smiling.