Clan is the term by which the Neanderthals describe themselves in the Earth's Children series. "Clan" can also describe the smaller tribe that they live with which is usually named after the leader. For example, Ayla is adopted into Brun's clan.
Jean Auel's books have been commended for their anthropological authenticity and their ethnobotanical accuracy. However, recent archaeological research may suggest that some prehistorical details in the series are inaccurate and others fictional, and that specifications of prehistorical milestones are sometimes arbitrary and inconsistent. For example, the differences between Neanderthals and Homo sapiens may have been exaggerated or underestimated in the series; it has been found that Neanderthals had a hyoid bone and may thus have been capable of using vocal language and not as dependent on sign language as portrayed in the series (the existence of a Neanderthal hyoid bone wasn't confirmed until 1983, some years after the first book in the series was published).
Neanderthals in the Earth's Children series are described as short, but enormously powerful people with darkish skin, thick dark brown body hair, overhanging brow ridges, prognathous mouths that jut out like short jaws, very little neck, and bowed legs. Though they possess incredible muscular strength and very thick, strong bones, they are capable of the precise and gentle movement needed to craft tools, weapons, and clothing. However, their shoulder joints do not rotate fully; using weapons that rely on rotational arm movement such as slings or bolas is said to be very difficult for them. Unlike the Others (cromagnon humans), the Clan are not able to vocalize fully, and rather than speaking and using hand gestures for emphasis, they speak using complex sign language with noise for emphasis. Because of this heavily back-brained physiology, they are nearly incapable of grasping abstractions in all forms, and possess a different signal for every plant, animal, type and degree of weather, shade of color and so on.
Their use of herbal medicine is highly advanced, but as a rule, practiced only by the female descendents of medicine women. During the course of the books, it is revealed they have at least some knowledge of CPR, bonesetting, birth, miscarriage, abortion, contraception, fever and infection, arthritis, blindness and more, all of which are approached with varying degrees of finesse. They are also said to make highly potent use of plants such as datura to make themselves more suggestible to the influence of the spirit world during religious ceremonies to honor the spirits of nature they worship.
All members of the Clan are assigned the protection of a Totemic spirit shortly after they are named and accepted at eight days old. Because social power lies entirely within the hands of the men, and the Clan believe that pregnancy is caused by the defeat of a woman's Totem spirit by a man's, female totems are typically small prey animals, while men are assigned the protection of carnivores and more powerful creatures. Examples of female totems include the beaver, tawny owl, saiga antelope, rabbit, and guinea pig, and male totems include the gray wolf, woolly rhinoceros, cave lion, and aurochs (though the full list of possibilities includes every animal known to the Clan.)
Gender roles among the Clan are rigidly enforced, not only by social convention, but by the shape of their brains. All men and women of the Clan are born with the knowledge of their ancestors already stored in the heavy occipital bun on the rear of their skull, though they cannot access this knowledge until a few years after birth. Because of the enlarged rear brain and small frontal lobe they are said to possess, innovation is not only difficult, but sometimes entirely impossible for them, and when they are forced to adopt new ideas, they cling unswervingly to them. Men are not only unwilling, but entirely unable to perform the survival tasks women are charged with, and vice versa.
Men assume full social control over all women upon reaching adulthood, and are expected to keep the women in line and enforce their respect. Any woman must obey any command given by any man, at any time, as quickly as possible, or face the consequences. When they wish to address an adult man, they must sit on the ground with head bowed and wait to be acknowledged before speaking; likewise, women are not to contradict, or even look directly at men without powerful reason, and a woman who violates their law-by-tradition or who fails to respond appropriately may be struck or cuffed to remind her of her place. Women are excluded from the Clan's religious life, though they are not entirely without power, and the wild imbalance is accepted without complaint by the women. Though it is unspoken, there is understanding that without women, the Clan would very quickly die, not only because they are the ones who give birth, but because men are incapable of learning to cook, skin food, gather plants, learn medicine, create clothing, baskets, and almost all other daily activities.
They are also not a compassion-less people. Children are reared with universal love and affection, and regardless of gender, are tolerated in all their behavior by adults. When children are punished, it is most often with being ignored for a short time to show that their behavior is not praiseworthy, and even men (who otherwise maintain impenetrable stoniness) relax their tough exteriors around the very young members of their extended families. They care for their sick, and though men have control over the women, it is considered ugly and unmasculine for a man to lose his temper in response to a women, or go beyond acceptable levels of discipline with them. Though men assume full societal power, they also assume a great deal of responsibility, just as the women do, each forming half of an incredibly complex social balance.
The Clan venerate animal spirits, and above all, the spirit of the Cave Bear, who they call Ursus. Their legends and stories indicate the belief that it was the spirit of the Cave Bear who first taught man to live in caves and wear fur, as he does, and to store food for winter, and it is heavily implied that these legends take place at the dawn of the Ice Age.