LeGuin’s depiction of a race of people without gender is at once revolutionary and deeply invested in notions of strict cultural divisions of people along normative gender lines. On Gethen, LeGuin suggests that the lack of static sexual organs and the ambivalent nature of the sexual anatomy an individual may develop during kemmer have resulted in a society without gender. LeGuin introduces the cisgendered male Genly, who comes from a patriarchal culture with a division of labor determined by gender roles, into the genderless society on Gethen to explore how and what elements of culture and civilization are informed by gender.

Although some critics interpret the Gethen people as progressively sexually fluid, LeGuin’s characterization of Gethen culture has also been criticized for conflating sexual anatomy with gender identity and for its heterosexual portrayal of sexual intimacy; Gethenian mates always assume discrete “male” and “female” identities during kemmer. This reduces the spectrum of both gender and sexual identities to the same binary that LeGuin seeks to criticize. LeGuin even represents gender and sexuality at once in the book through the yin/yang symbol, male and female, separated into hard demarcations of black and white but intertwined playfully. She does not allow for the gray areas described by a graduated spectrum.