Growth and Development
This novel explores the fundamental debate of "nature" versus "nurture" by examining life on Gethen. It questions which cultural characteristics are taught and passed down through generations and which stem directly from one's environment. On Gethen, the absence of gender distinctions allows for a society with fewer limitations on where individuals can go and what careers they can pursue. The phrase "The king is pregnant" might sound unusual to those from Earth, where the roles associated with "king" and "pregnancy" differ significantly. However, on Gethen, such an announcement is not surprising. What astonishes them is that humans can engage in sexual activity daily, unlike their own monthly cycles. The infrequency of sexual activity results in Gethenians being intensely affected by their "kemmer" or sexual cycle. Without the daily distraction of sexuality, they focus more on unity rather than differences. Gethenians, known for their spiritual enlightenment, have developed the ability to gather and predict the future, although they find little practical use for this skill. Meanwhile, advanced members of the Ekumen have learned to connect with others' minds, a skill rooted in recognizing differences. Another key factor in Gethen's development is its Ice Age climate. The absence of birds means they lack a natural model for air travel, hindering their progress toward space exploration. Much of their physical energy is devoted to generating heat, resulting in less developed muscles. As illustrated in Chapter 17's Creation Myth, where warmth is derived from a house built with Edondurth's brothers' bodies, Gethenians have learned to be more resource-conscious, as wastefulness can be a matter of survival.

Sex Roles
When Genly Ai's Gethenian friend inquires about the differences between men and women on Earth, Genly replies, "It's extremely hard to separate the innate differences from the learned ones. Even where women participate equally with men in the society, they still do all of the child-bearing, and so most of the child-rearing...." After contemplating the minimal differences between men and women and their distinct societal roles, he concludes, "In a sense, women are more alien to me than you are. With you I share one sex, anyhow...." One of the most debated concepts in this novel is the portrayal of a race on Gethen that is free from the constraints of gender identity expectations. Their traits evolve based on the environment and circumstances. This presents a challenge for Genly Ai, who was raised on Earth, in effectively fulfilling his role as an envoy, as he struggles to understand their thoughts. He is accustomed to viewing human identity in binary terms, categorizing people as either similar or different from him, which leads to some unusual and incorrect assumptions about his hosts. For instance, he perceives their historical lack of war as a flaw rather than a strength: "They lacked, it seemed, the capacity to mobilize. They behaved like animals, in that respect; or like women. They did not behave like men, or ants." Genly's inability to perceive them accurately results in disappointment early in the story when Estraven does not act as assertively with the king on his behalf as Genly expects. Although Gethenians develop sexual identities every twenty-six days, and pregnancy can assign a maternal role during gestation and nursing, they are not truly asexual; they are ambisexual. Instead of having no gender, they experience both. Due to the limitations of the English language, it is challenging for readers to fully grasp this concept of sexlessness, as characters are consistently referred to as "he" in the narrative.

Politics
As an outsider, Genly Ai is unfamiliar with the cultural norms in Karhide and Orgoreyn....