Human sexuality holds a great interest for anthropologists. As a biological reality and a reproductive force, sexuality affects all humans. However, there is much diversity in the experience, expression, and interpretation of sexuality throughout the world. Using a holistic perspective, meaning that various aspects of the human experience are considered to be interrelated and interdependent, anthropologists consider biological as well as cultural factors in an attempt to understand and explain the dynamics of human sexuality.
Some anthropologists are particularly interested in the interrelationship between sexuality and human physical and cultural evolution. Physical changes in the human species over time have influenced the nature of sexuality. In turn, changes in sexual practices may have had an impact on the physical changes that humans have undergone.
If sexuality is a biological reality, it is nevertheless interpreted through the various cultural frameworks in which it is experienced. Therefore, human culture has an enormous impact on the diverse meanings attributed to sexuality and sexual behaviors. Anthropologists consider sexuality to be a central aspect of human social organization that influences, and is influenced by, various other aspects of society such as food-getting, family structure, and religious belief.
Human Evolution and Sexuality
While all mammals, including humans, reproduce sexually, humans exhibit different patterns of sexuality than other members of this class of animals. Even among the primates—the order in which humans are categorized in the Linnaean taxonomic system and that includes apes and monkeys—humans are distinct when it comes to patterns of sexuality.
These differences are considered by anthropologists and other scientists as being representative of adaptive strategies, or coping mechanisms, that humans have adopted over time in response to environmental, bio-logical, and social pressures. While some scholars focus on these pressures individually, the discipline of anthropology generally acknowledges that they are likely to be interconnected. In other words, there may not be one individual source for the uniqueness of human sexuality.
In contrast to many other mammals, for example, human females are sexually receptive throughout the year, regardless of whether or not they are fertile. This characteristic is related to the loss of estrus among human females. That is, at some point in their evolutionary history, human females gained the physical capacity to conceal ovulation. The period of time during which females are fertile became unknown to males and, in most cases, to females themselves. The process whereby females gained concealed ovulation may be linked to other physical changes that occurred through evolution such as the ability to walk upright and the loss of body hair.
As a byproduct of this change, humans mate throughout the year and sexuality has implications that range further than its reproductive function. The social impact of this trait touches on marriage, family structure, economic structure, and so forth. A related trait, for instance, and another distinction between humans and many other mammals, is that humans demonstrate a tendency for pair bonding, where a male and a female collaborate in the raising of offspring.
What is the adaptive advantage of these interrelated traits? One answer may be that since humans have a longer gestational period and offspring have a longer maturation period than those of other mammals, collaborative parenting may lead to a higher success rate in the raising of young. Human babies are born defenseless and unable to survive on their own. Parents must therefore feed and shelter their young for a longer period of time. The capacity for year-round mating may be one factor that facilitates the maintenance of these pair bonds since the male and the female mate repeatedly, even during times where there is no possibility for reproduction.
Another example of the correlation between physical changes and human sexuality is sexual selection. Sexual selection refers to the process whereby physical traits that are highly appealing to members of the opposite sex will give the carrier a higher chance of obtaining mating partners and of passing on his or her genetic material to the following generation. Along with natural selection, where individuals with traits that help them survive stand a better chance of living long enough to reproduce and pass on the genes for those traits to the following generation, sexual selection is considered by anthropologists to be an important factor in the genetic variation of the world’s human population.
Some scientists claim to have found traits that are universally considered to be appealing, such as body symmetry and the appearance of good health. This might lead anthropologists to conclude that humans are predisposed to desire certain traits in sexual partners. However, culture plays a vital role in this process as well. Cultural ideals about beauty in males and females play a large role in what is considered appealing or what is considered to be a sign of good health. Within a society, these ideals may change over time.
Culture and Sexuality
For humans, sexuality is more than a reproductive force. Humans engage in sexuality for pleasure, love, or other reasons. These reasons may supplement, or even replace, the desire to produce offspring. Nevertheless, the reproductive potential of sexual relations, particularly in the case of opposite-sex relations, affects the ways in which sexuality is experienced, even when it is performed for other reasons. At the social and cultural level, sexuality encompasses a wide range of human experiences, from sexual relations themselves to individual roles and identity.
The cultural experience of human sexuality is quite diverse and varies alongside myriad factors that stem from local cultural adaptations. These factors include subsistence patterns, kinship systems, and worldview. Therefore, while sexuality is a universal phenomenon, there is variation with regards to its actual functions within specific cultural contexts.
A society’s subsistence pattern, or how societies obtain and distribute essential resources, may influence sexuality by providing a context to which people must adapt to survive. Subsistence patterns such as foraging, where people obtain their resources by hunting wild game and gathering wild plant foods, or agriculture, where people grow crops on permanent plots of land, entail different kinds of divisions of labor between men and women. In most cases, women will take on tasks that are amenable to their capacities for bearing and nursing children. There are exceptions to these patterns; societies vary in their flexibility toward the types of work that men and women perform.
This sexual division of labor has implications for a society’s kinship system, or how societies regulate marriage and family structure. If tasks and resources must be managed for the survival of the group, social relations, including sexual relations, must be managed to avoid social conflict due to sexual tensions and jealousy and to provide a framework within which resources are shared.
Marriage, a human universal, is a means whereby sexual relations are sanctioned and recognized within a society. This institution takes different forms, however. Marriage can be monogamous, taking place between two individuals, or polygamous, meaning that one individual may have more than one spouse. There are two types of polygamy: polygyny, the more common form, permits a man to have two or more wives, whereas polyandry allows for a woman to have two or more husbands. Monogamous marriages are the statistical norm throughout human societies. However, many societies place a high value on polygamy as an ideal form of marriage. Regardless of the form it takes, marriage involves mutual responsibilities among spouses, including sexual obligations.
In fact, failure to meet sexual obligations is grounds for divorce in some societies.
Across the ethnographic spectrum, there is a range of expectations on sexual behavior before, during, and after marriage. These expectations are often different for males and females. In many cases, female virginity at marriage is highly prized and is a reflection of family honor. On the other hand, societies such as the Canela of the Amazon allow teens of both sexes to engage in sexual experimentation before marriage and encourage extramarital sex. Finally, there exist, in some cases, taboos against sex after the death of a spouse, particularly in the case of widows.
While traditional anthropological literature referred to marriage as a union between at least one man and one woman, same-sex unions that meet the criteria for the anthropological definition of marriage exist. In some African societies, such as the Nuer and the Zande, same-sex unions of varying levels of formality occurred. Today, same-sex marriages are being legally recognized in some Western nations such as Belgium, the Netherlands, and Canada.
Another human universal that is related to kinship is the incest taboo. In all societies, sexual relations or marriage are forbidden between people who are considered to be closely related. The degree of closeness is culturally determined. In most cases, forbidden sexual partners include parents, grandparents, siblings, and children. Certain categories of cousins, aunts, and uncles are frequently included. Depending on the kinship system, other individuals may be off limits because of their names or other culturally defined parameters.
There are various theories that explain the existence of the incest taboo. One concerns congenital problems that may arise through inbreeding. Another explanation is the “aversion theory,” which postulates that children growing up together, such as brothers and sisters, will develop a sexual aversion to each other. Finally, the “alliance theory” states that it is advantageous for any group to form alliances with other groups. Marriage outside the immediate family establishes and maintains social ties between groups and provides a wider network of people upon which a family may draw in times of need or conflict.
If subsistence patterns and kinship systems help explain the practicality of certain sexual patterns, worldviews give meaning to sexuality. A worldview is a set of ideas that explain the world and prescribe appropriate behavior. An example of a worldview is religion, or a set of beliefs and practices regarding the human connection with divine or supernatural forces.
Regulations on sexual behavior that may appear to an outsider to be simple adaptations to local realities or arbitrary sanctions may carry greater significance to members of a society because of a shared world-view. Practices such as same-sex relationships, masturbation, oral sex, anal sex, sex during menstruation, sequential sex, group sex, spouse exchange, use of pornography, prostitution, and sexual violence are prescribed, prohibited, or relegated to particular circumstances according to beliefs and assumptions about what is appropriate and normal sexual conduct.
In fact, some acts that would be considered to be sexual in nature by Western standards are not considered sexual at all in their respective cultural contexts. For example, anthropological informants in African societies such as the Lesotho of South Africa have indicated that sex is defined by the contact between a penis and a vulva. Therefore, genital contact between members of the same sex is not considered to be sex.
While norms exist in every culture regarding sexual behavior, these norms represent a cultural ideal. In practice, there is variance from the norms in some individuals. Societies differ in the manner in which individuals believed to have transgressed sexual norms are treated. Sanctions may range from divorce, as in many Western societies in cases of adultery, to social stigma, as in the case of a Canela individual who refuses sexual access to another, to corporal punishment, as in cases of homosexuals who are persecuted in nations where homosexual activity is illegal.
Positions for intercourse are also socially prescribed and are often tied in with beliefs about what is normal or natural. While it is extremely difficult to observe sexual intercourse given the human tendency to conduct sexual acts in private, ethnographers have collected data on the frequency of particular positions. The most common positions for heterosexual intercourse are the missionary position, with the man lying on top of the woman, woman-on-top, man and woman side by side and face to face, and rear entry, with the man penetrating the woman’s vagina from behind. The desire for orgasm also varies from culture to culture according to beliefs about the nature and purpose of sexuality. These beliefs are often connected to ideas about sex and gender identity, beliefs about the process of reproduction, or the relative social positions of males and females.
Through ethnographic studies, social and cultural anthropologists have found that there exists a great diversity with respect to the ways in which sexuality is discussed with children or among adults. From sex-positive societies such as the Trobriand Islanders and the Canela, where children have opportunities to observe adults engaging in sexual intercourse, to sex-negative societies such as that of Inis Beag, Ireland where sex was rarely mentioned and was the cause of great anguish, there exist many patterns of ideas and practices.
Human sexuality is a complex subject but it is crucial to an understanding of the human experience. Today, as in the past, conflicts arise between and within societies regarding the appropriateness of various forms of sexual conduct, the roles of the sexes, and so forth. Since one’s society so strongly influences an individual’s perception of what is normal and natural sexual behavior, it can be difficult to accept the sexual practices of an unfamiliar culture. Unbiased anthropological inquiries into the evolution of human sexuality and the diversity of sexual norms and practices may help to shed light on these conflicts. However, since sexuality is such a central part of human life and touches on core aspects of group and individual identity, it is impossible to predict whether these conflicts will ever be resolved.
- Diamond, J. (1997). Why is sex fun: The evolution of human sexuality. New York: Basic Books.
- Middleton, D. R. (2002). Exotics and erotics: Human cultural and sexual diversity. Prospect Heights, IL: Waveland Press.
- Suggs, D. N., & Miracle, A. W. (Eds.). (1993). Culture and human sexuality. Pacific Grove, CA: Brooks/Cole.