Friday, Jul 24, 2026 The claims desk. Receipts included. POWERED BY LENZ
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HISTORY

The Claim

During the 1930s and 1940s, the Japanese government linked eugenics to nationalism by arguing that Japan's national strength depended on the biological quality of its citizens.

The Short Version

The historical record supports the core point. Japanese officials and lawmakers in the late 1930s and 1940s explicitly connected eugenic ideas to national power, arguing that the population's hereditary and physical quality affected the nation's strength. The wording is somewhat broad, though, because wartime nationalism also drew on other themes besides biology.

Caveats

  • The clearest documentary support comes from the 1940 National Eugenic Law and surrounding debates, so the claim is strongest for that policy context rather than every official statement across both decades.
  • "Depended" slightly overstates the evidence if read as exclusivity; biological quality was presented as one important basis of national strength, not the only one.
  • Ideological rhetoric and practical implementation were not identical; the state's eugenic-nationalist framing was broader than the actual scale of enforcement.

The Receipts

  1. 第1章 国民優生法の制定過程

    衆議院

  2. 第1編 旧優生保護法の立法過程

    参議院

  3. Eugenic Protection Law in Japan (Latest Revised Edition)

    Institute of Population Problems, Ministry of Health and Welfare (Japan)

  4. Eugenics in Modern and Contemporary Japan

    Ebisu: Études japonaises (OpenEdition Journals)

  5. Eugenics in East Asia: Nationalism and Biopolitics in Modern Japan, China, and Korea (chapter on Japan)

    Open Book Publishers

  6. Eugenic Modernity and the Creation of New Japanese

    Anthropological Quarterly (via professorjenniferrobertson.com)

  7. 【法学8】(歴史)戦前~戦後日本の優生法制(三成美保)

    国立ジェンダー研究所(ch-gender.jp)

  8. 優生保護法下における精神科医療及び精神科医の果たした役割に関する検証報告書

    日本精神神経学会

  9. What We Must Learn from Japanese Eugenic Protection Act

    University of Hawai‘i at Mānoa

  10. Politics of Birth Control and Eugenics in Interwar Japan

    Cornell University eCommons

+ 11 more sources — see the full list on Lenz

Filed Under

Japan

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