marriage, a legally and socially sanctioned union, usually between a man and a woman, that is regulated by laws, rules, customs, beliefs, and attitudes that prescribe the rights and duties of the partners and accords status to their offspring (if any). The universality of marriage within different societies and cultures is attributed to the many basic social and personal functions for which it provides structure, such as sexual gratification and regulation, division of labour between the sexes, economic production and consumption, and satisfaction of personal needs for affection, status, and companionship. Perhaps its strongest function concerns procreation, the care of children and their education and socialization, and regulation of lines of descent. Through the ages, marriages have taken a great number of forms. (See exchange marriage; group marriage; polyandry; polygamy; tree marriage. See also common-law marriage.)
By the 21st century the nature of marriage in Western countries—particularly with regard to the significance of procreation and the ease of divorce—had begun to change. In 2000 the Netherlands became the first country to legalize same-sex marriages; the law went into force on April 1, 2001. In the ensuing years, numerous other countries—including Canada (2005), France (2013), the United States (2015), and Germany (2017)—followed suit. In addition, some countries extended benefits and obligations to same-sex couples by means of a registered partnership or civil union, both of which terms meant different things in different contexts.
In the biological evolutionary scale, the more complex the species, the longer the offspring is dependent on its mother for survival from the time of birth to maturity. Human beings, at the top of the evolutionary scale, require the most time of all species to reach maturity. This imposes increased duties on human parents for the care of their children, and marriage traditionally has been seen as the institution best suited to fulfill these parental duties and responsibilities.
Marital customs and laws
Some form of marriage has been found to exist in all human societies, past and present. Its importance can be seen in the elaborate and complex laws and rituals surrounding it. Although these laws and rituals are as varied and numerous as human social and cultural organizations, some universals do apply.
The main legal function of marriage is to ensure the rights of the partners with respect to each other and to ensure the rights and define the relationships of children within a community. Marriage has historically conferred a legitimate status on the offspring, which entitled him or her to the various privileges set down by the traditions of that community, including the right of inheritance. In most societies marriage also established the permissible social relations allowed to the offspring, including the acceptable selection of future spouses.
Until the late 20th century, marriage was rarely a matter of free choice. In Western societies love between spouses came to be associated with marriage