One of the most puzzling questions in anthropology is why marriage and incest taboos are nearly universal institutions in human societies. In order to answer these questions, their many theories will be explained and compared.
There are many theories for the universal institution of marriage. It solves a few problems between men and women, but these problems cannot be considered the prime motivation for marriage as an institution. Some of these problems include sharing the products of gendered labor, caring for extremely dependent offspring and minimizing sexual competition (Ember and Ember, 2007, pg.163-164). If sharing the products of labor was the cause of the development of marriage, why did humans not evolve a more efficient system of distribution? If minimizing sexual competition was the goal why didn't humans rotate sexual partners within the group so that no one individual gets more copulations than the rest? Humans can look to their mammalian and avian counterparts to see more persuasive explanations for the evolution of long term pair bonding or marriage. Long term pair bonds are most closely correlated to species in which females cannot simultaneously feed themselves and their newly birthed young. Females in these species need to enlist the help of a male so that they can mutually support their offspring. In many bird species, the female cannot leave her nest without exposing her young to danger, so she pair bonds with a male so that they can take turns taking care of young. Human females cannot hunt or forage while nursing or babysitting; they require a male to provide the needed calories (Ember and Ember, 2007, pg.163-164).
The incest taboo is an equally interesting question. There are many theories to explain it, ranging from Freud's Psychoanalytic theory to Malinowski's Functionalism and Westermark's theory of childhood sexual aversion. Freud believed that the incest taboo originated from a reaction to unconscious but unacceptable desires. Malinowski believes that the incest taboo was needed to stabilize family relations and preserve society. The most convincing theory to date is the inbreeding theory. It says that the main reason that closely related individuals do not marry or have sexual relations is that such unions often produce unviable or deformed offspring. The production of such offspring would render these unions evolutionarily unfit (Ember and Ember, 2007, pg. 167-170).
Sex and Gender are two very different concepts in anthropology. Sex refers to the biological differences inherent in males and females. Gender is a socially and culturally defined construction and may be different between different societies. In many different cultures, gender differences do not always align with sexual differences. Many cultures, in fact, see male and female as opposing ends of a continuum; there may be many intermediate 'genders' between male and female (Ember and Ember, 2007, pg. 145).
These social constructions may be very difficult to separate from the biological realities of maleness and femaleness. For example, a cross-cultural study done by anthropologists recorded that boys within many societies tend to be more aggressive than the females within that same culture. Females, in turn, tend to be more nurturing in those cultures. Since these differences are universal, are they a product of biological differences? Or do all societies need men and women for different roles and thus socialize their children appropriately? A study on Australian aborigines has shown a high level of female aggression, leading many researchers to speculate that behavioral differences are cultural in origin (Ember and Ember, 2007, pg. 154-155).
The Navajo of Southwestern United States traditionally recognized four genders and sexual relations among these different genders were not considered homosexual except in Western eyes. These genders are different than sex differences since they encompassed different versions of maleness and femaleness (Ember and Ember, 2007, pg. 157). The Iroquois had a third gender in their culture. This individual usually wore both male and female clothing and tended to spiritual matters (Ember and Ember, 2007, pg. 146-146). These differences between cultures, of socialization of the sexes as well as their concepts of gender, show that gender is more than just the biological differences we see between men and women.
Ember, C.R., &Ember, M. (2007). Cultural Anthropology (12ed.). Englewood Cliffs, N.J.: Prentice-Hall