Judith Butler says that Beauvoir's formulation that "One is not born, but rather becomes, a woman" distinguishes the terms "sex" and "gender". Borde and Malovany-Chevalier, in their complete English version, translated this formulation as "One is not born, but rather becomes, woman" because in this context (one of many different usages of "woman" in the book), the word is used by Beauvoir to mean woman as a construct or an idea, rather than woman as an individual or one of a group. Butler says that the book suggests that "gender" is an aspect of identity which is "gradually acquired". Butler sees The Second Sex as potentially providing a radical understanding of gender.
Sex researcher Alfred Kinsey was critical of The Second Sex, holding that while it was an interesting literary production, it contained no original data of interest or importance to science.
Deirdre Bair describes criticism of The Second Sex in her "Introduction to the Vintage Edition" in 1989. She says that "one of the most sustained criticisms" has been that Beauvoir is "guilty of unconscious misogyny", that she separated herself from women while writing about them. Bair says the French writer Francis Jeanson and the British poet Stevie Smith made similar criticisms: in Smith's words, "She has written an enormous book about women and it is soon clear that she does not like them, nor does she like being a woman." Bair also quotes (as "oft-repeated criticism") British scholar C. B. Radford who thought Beauvoir was "guilty of painting women in her own colors" because The Second Sex is:
primarily a middle-class document, so distorted by autobiographical influences that the individual problems of the writer herself may assume an exaggerated importance in her discussion of femininity.
Classicist David M. Halperin writes that Beauvoir gives an idealized account of sexual relations between women, suggesting that they reveal with particular clarity the mutuality of erotic responsiveness that characterizes women's eroticism.
Literary scholar Camille Paglia praised The Second Sex, calling it "brilliant" and "the supreme work of modern feminism."