Trans medicine has historically naturalized a heterosexual binary model of gender by treating variation as aberrant. Gender dysphoria, the current psychiatric diagnosis that often facilitates trans medicine, is represented by mental health experts and LGBTQ groups as a superficial semantic shift in this tradition. Based on in-depth interviews with experts who crafted gender dysphoria for the fifth edition of the Diagnostic and Statistical Manual (DSM-5) in 2013 and archival study of the experts’ research process, I find far more than semantics at stake. Because experts had an imperative for evidence-based revisions to the DSM-5 and an underdetermined research based on gender identity development, their revision affirms gender variation as natural and non-pathological. Gender dysphoria is maintained as a mental disorder because experts insist on its importance for the institutional legitimation of trans people, not because gender variation is understood to be pathological. This move toward treating gender variation as a flexible spectrum of illness and wellness required a new scientific interpretation of evidence. This interpretation (1) finds underdetermined research to be credible evidence of natural variation and (2) applies this variation simultaneously to traits (like gender) and also to health status. Consequently, natural variation becomes a scientific finding.

跨医学历史上通过将变异视为异常来归化异性二元性别模型。性别焦虑症是目前经常促进跨医学的精神病学诊断，被心理健康专家和 LGBTQ 团体代表为这一传统中的表面语义转变。基于对第五版《诊断和统计手册》中性别焦虑症专家的深入访谈(DSM-5) 在 2013 年和专家研究过程的档案研究中，我发现所涉及的远不止语义。由于专家们迫切需要对 DSM-5 进行基于证据的修订，并且基于性别认同发展的研究尚未确定，因此他们的修订确认性别变异是自然的和非病态的。性别焦虑被认为是一种精神障碍，因为专家坚持认为它对跨性别者的制度合法性很重要，而不是因为性别差异被认为是病态的。这种将性别差异视为疾病和健康的灵活范围的转变需要对证据进行新的科学解释。这种解释 (1) 发现不确定的研究是自然变异的可靠证据，并且 (2) 将这种变异同时应用于性状（如性别）和健康状况。因此，自然变异成为一项科学发现。