A prominent theme in The Clan of the Cave Bear revolves around the "nature versus nurture" debate, questioning whether behavior is predominantly shaped by genetics or the environment. Auel suggests that The Clan ensures its survival by rigidly following traditional rules and gender roles, leading to an inability to adapt to new situations. For example, Clan women do not hunt because it is not part of their role; they lack any desire to do so. Auel depicts Clan women as naturally submissive and physically unable to learn new skills.

Ayla's presence disrupts the Clan's societal norms and traditions. She feels compelled to challenge the Clan's customs, finding them irrational. While she acts like an ideal Clan woman, Ayla maintains a spirited nature and refuses to fully submit to the patriarchal society. Although she is punished for her rebellion, her actions show other Clan women that they can hunt, heal, and stand up against abuse and exploitation. As a result, due to the threat she poses to the patriarchal order, she is exiled by the novel's end.

Ayla's struggle to fit into Clan society underscores a theme Auel delves into: the conflict between personal desires and societal expectations. Ayla longs for love from Creb and Iza and seeks acceptance from the Clan. However, her personal aspirations for freedom, independent thinking, and exploration clash with the Clan's demands for controlling its members to maintain communal harmony. As a result, she endures beatings, rape, and curses because she values her own feelings and the needs of those close to her over the community's insistence on order and unity.

Auel critiques modern American society, which promotes individual rights while simultaneously encouraging obedience and adherence to laws. This conflict between personal and societal needs is embodied in the character of Broud. Driven by revenge, Broud ignores the well-being of his community and its members. Ultimately, his actions result in the expulsion of a skilled medicine woman and provoke the wrath of the spirits, leading to the cave's destruction, Creb's death, and forcing Broud's people to become wanderers once again.

Auel's novel has sparked debate, particularly concerning its portrayal of Neanderthal culture. Many anthropologists contend that Auel's scientific foundation is weak and inaccurate. There is no evidence supporting claims that Neanderthals were bowlegged, had limited arm mobility, or were incapable of speaking, crying, or laughing. These concepts are entirely Auel's creations. She uses these baseless assumptions to explain the extinction of Neanderthals, suggesting that cultural stagnation, or a society's failure to evolve and adapt, results in extinction. The narrator in Auel's work states that the Clan cannot learn new things because it would require larger brains, complicating childbirth. Additionally, she hints that their downfall is inevitable due to their inability to share household responsibilities or innovate hunting methods.

This narrative mirrors Auel's perspective on American culture in the mid-1970s. At that time, inflexible economic strategies, social policies, and cultural mindsets that resisted change led to high inflation and unprecedented unemployment. Through the metaphor of the Clan, Auel suggests that American society needs to stay adaptable and open to new ideas to succeed in the future.

For many readers, the Clan's strict gender roles are both baffling and offensive. Writing during the height of the feminist movement, Auel explores the issues that arise from male-dominated societies. Patriarchal systems can create numerous social and political problems, and Auel seeks to expose these issues through her narrative. For example, women in the Clan lack rights, have no say in the power structure, and are required to be completely subservient to men in all aspects.

Broud embodies the dangers...