The Swedish author and educator Ellen Key (1849–1926) became one of the most prominent writers on educational matters in Europe at the turn of the 20th century following the publication of The Century of the Child in 1900. It is less widely known, however, that the pioneer of progressive education and children’s rights also advocated the improvement of humanity through eugenics, and publicly endorsed the foundation of the Swedish Institute for Racial Biology in 1921. In previous research, Key’s stance on eugenics has been explained by her evolutionist worldview, influenced by her reading of scientists and philosophers such as Francis Galton (1822–1911) and Herbert Spencer (1820–1903). But can her support for eugenics solely be reduced to th...