Vertebrate bodies are sexually neutral, with gonadal hormones producing sexual characteristics

Evidence

Many experiments have demonstrated that varying the endocrine milieu makes it possible to act on sex determination; other grafting and castration experiments carried out on adult animals have led to the modern theory of sexuality: in male and female vertebrates, the soma is identical and can be considered a neutral element; the action of the gonad gives it its sexual characteristics; some of the secreted hormones act as stimulants and others as inhibitors; the genital tract itself is somatic, and embryology shows that it takes shape under the influence of hormones from bisexual precursors. Intersexuality exists when hormonal balance has not been realized and when neither of the two sexual potentialities has been clearly accomplished. — Simone de Beauvoir, The Second Sex, 89

Categorization

• DEFINE: Lays out the ‘modern theory of sexuality’ — the body as neutral soma that hormones shape — which undercuts the claim that sex is an essential biological given.
• SEED: Article angle: how a biological fact (the neutral soma made sexual by hormones) was absorbed or resisted by mid-century feminism and gender theory.
• DEEPTHINKING: This is the scientific warrant for Beauvoir’s whole argument that anatomy is not destiny — the body is neutral matter shaped into either sex, so sex itself is a process rather than an essence.
• XREF: connects to: Sex determination is genotypical, but both sexes begin from identical undifferentiated tissue — Simone de Beauvoir, The Second Sex, 89