USCA11 Case: 18-13592 Document: 304-1 Date Filed: 12/30/2022 Page: 96 of 150
Dr. Ehrensaft’s expert testimony illuminated the differences between the School District’s definition of “biological sex” and the scientific community’s biological understanding of sex. Dr. Ehrensaft testified that “[b]y the beginning of the twentieth century scientific research had established that external genitalia alone—the typical criterion for assigning sex at birth—[was] not an accurate proxy for a person’s sex.” Doc. 166-3 ¶ 20. Instead, she continued:
[M]edical understanding recognizes that a person’s sex is comprised of a number of components including: chromosomal sex, gonadal sex, fetal hormonal sex (prenatal hormones produced by the gonads), internal morphologic sex (internal genitalia, i.e., ovaries, uterus, testes), external morphological sex (external genitalia, i.e., penis, clitoris, vulva), hypothalamic sex (i.e., sexual differentiations in brain development and structure), pubertal hormonal sex, neurological sex, and gender identity and role.
Id. As with components like chromosomal sex or external morphological sex, Dr. Ehrensaft testified, gender identity is “immutable” and “has a biological basis.” Id. ¶ 25; Doc. 166-5 at 38.
After spelling out these numerous biological components of sex, Dr. Ehrensaft testified: “When there is a divergence between these factors, neurological sex and related gender identity are the most important and determinative factors” for determining sex. Doc. 166-3 ¶ 20. The School District did not offer any evidence to rebut this expert testimony.
