Kinship in the context of Homogeneous binary relation

Social stratification refers to a society's categorization of its people into groups based on socioeconomic factors like wealth, income, race, education, ethnicity, gender, occupation, social status, or derived power (social and political). It is a hierarchy within groups that ascribe them to different levels of privileges. As such, stratification is the relative social position of persons within a social group, category, geographic region, or social unit.

In modern Western societies, social stratification is defined in terms of three social classes: an upper class, a middle class, and a lower class; in turn, each class can be subdivided into an upper-stratum, a middle-stratum, and a lower stratum. Moreover, a social stratum can be formed upon the bases of kinship, clan, tribe, or caste, or all four.

Genealogy (from Ancient Greek γενεαλογία (genealogía) 'the making of a pedigree') is the study of families, family history, and the tracing of their lineages. Genealogists use oral interviews, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kinship and pedigrees of its members. The results are often displayed in charts or written as narratives. The field of family history is broader than genealogy, and covers not just lineage but also family and community history and biography.

The record of genealogical work may be presented as a "genealogy", a "family history", or a "family tree". In the narrow sense, a "genealogy" or a "family tree" traces the descendants of one person, whereas a "family history" traces the ancestors of one person, but the terms are often used interchangeably. A family history may include additional biographical information, family traditions, and the like.

The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflicting theoretical understandings of social and kinship structures, and also reflecting the problematic application of this concept to extremely diverse human societies. Its concept is often contrasted by anthropologists with other social and kinship groups, being hierarchically larger than a lineage or clan, but smaller than a chiefdom, ethnicity, nation or state. These terms are similarly disputed. In some cases tribes have legal recognition and some degree of political autonomy from national or federal government, but this legalistic usage of the term may conflict with anthropological definitions.

In the United States (US), Native American tribes are legally considered to have "domestic dependent nation" status within the territorial United States, with a government-to-government relationship with the federal government.

Race is a categorization of humans based on shared physical or social qualities into groups generally viewed as distinct within a given society. The term came into common usage during the 16th century, when it was used to refer to groups of various kinds, including those characterized by close kinship relations. By the 17th century, the term began to refer to physical (phenotypical) traits, and then later to national affiliations. Modern science regards race as a social construct, an identity which is assigned based on rules made by society. While partly based on physical similarities within groups, race does not have an inherent physical or biological meaning. The concept of race is foundational to racism, the belief that humans can be divided based on the superiority of one race over another.

Social conceptions and groupings of races have varied over time, often involving folk taxonomies that define essential types of individuals based on perceived traits. Modern scientists consider such biological essentialism obsolete, and generally discourage racial explanations for collective differentiation in both physical and behavioral traits.

A clan is a group of people united by actual or perceived kinshipand descent. Even if lineage details are unknown, a clan may claim other descent from a founding member or apical ancestor who serves as a symbol of the clan's unity. Many societies' exogamy rules are on a clan basis, where all members of one's own clan, or the clans of both parents or even grandparents, are excluded from marriage as incest.

Clans preceded more centralized forms of community organization and government, and have existed in every country. Members may identify with a coat of arms or other symbol.

Behavioral modernity is a suite of behavioral and cognitive traits believed to distinguish current Homo sapiens from other anatomically modern humans, hominins, and primates. Most scholars agree that modern human behavior can be characterized by abstract thinking, planning depth, symbolic behavior (e.g., art, ornamentation), music and dance, exploitation of large game, and blade technologies, among others.

Underlying these behaviors and technological innovations are cognitive and cultural foundations that have been documented experimentally and ethnographically by evolutionary and cultural anthropologists. These human universal patterns include cumulative cultural adaptation, social norms, language, and extensive help and cooperation beyond close kin.

A person (pl.: people or persons, depending on context) is a being who has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts.

In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes.

The Normans (Norman: Normaunds; French: Normands; Latin: Nortmanni/Normanni) were a population arising in the medieval Duchy of Normandy from the intermingling between Norse Viking settlers and locals of West Francia. The Norse settlements in West Francia followed a series of raids on the French northern coast mainly from what is now Denmark, although some also sailed from Norway and Sweden. These settlements were finally legitimized when Rollo, a Scandinavian Viking leader, agreed to swear fealty to King Charles III of West Francia following the siege of Chartres in 911, leading to the formation of the County of Rouen. This new fief, through kinship in the decades to come, would expand into what came to be known as the Duchy of Normandy. The Norse settlers, whom the region as well as its inhabitants were named after, adopted the language, religion, social customs and martial doctrine of the West Franks but their offspring nonetheless retained many of their traits, notably their mercenary tendencies and their fervour for adventures. The intermixing between Norse folk and native West Franks in Normandy produced an ethnic and cultural "Norman" identity in the first half of the 10th century, an identity which continued to evolve over the centuries.

The Norman dynasty had a major political, cultural and military impact on medieval Europe and the Near East. The Normans were historically famed for their martial spirit, and eventually for their Catholic piety as adherents of the Catholic orthodoxy of the Romance community. The original Norse settlers adopted the Gallo-Romance language of the Frankish land they settled, with their Old Norman dialect becoming known as Norman, Normaund or Norman French, an important literary language which is still spoken today in parts of mainland Normandy (Cotentinais and Cauchois dialects) and the nearby Channel Islands (Jèrriais and Guernésiais). The Duchy of Normandy, which arose from the Treaty of Saint-Clair-sur-Epte, was a great fief of medieval France. The Norman dukes exercised independent control of their holdings in Normandy, while at the same time being vassals owing fealty to the King of France, and under Richard I of Normandy (byname Richard sans Peur, meaning "Richard the Fearless"), the duchy was forged into a cohesive and formidable principality in feudal tenure.

A generation is all of the people born and living at about the same time, regarded collectively. It also is "the average period, generally considered to be about 20–30 years, during which children are born and grow up, become adults, and begin to have children." In kinship, generation is a structural term, designating the parent–child relationship. In biology, generation also means biogenesis, reproduction, and procreation.

Generation is also a synonym for birth/age cohort in demographics, marketing, and social science, where it means "people within a delineated population who experience the same significant events within a given period of time." The term generation in this sense, also known as social generations, is widely used in popular culture and is a basis of sociological analysis. Serious analysis of generations began in the nineteenth century, emerging from an increasing awareness of the possibility of permanent social change and the idea of youthful rebellion against the established social order. Some analysts believe that a generation is one of the fundamental social categories in a society; others consider generation less important than class, gender, race, and education.

In social psychology, an interpersonal relation (or interpersonal relationship) describes a social association, connection, or affiliation between two or more people. It overlaps significantly with the concept of social relations, which are the fundamental unit of analysis within the social sciences. Relations vary in degrees of intimacy, self-disclosure, duration, reciprocity, and power distribution. The main themes or trends of the interpersonal relations are: family, kinship, friendship, love, marriage, business, employment, clubs, neighborhoods, ethical values, support, and solidarity. Interpersonal relations may be regulated by law, custom, or mutual agreement, and form the basis of social groups and societies. They appear when people communicate or act with each other within specific social contexts, and they thrive on equitable and reciprocal compromises.

Interdisciplinary analysis of relationships draws heavily upon the other social sciences, including, but not limited to: anthropology, communication, cultural studies, economics, linguistics, mathematics, political science, social work, and sociology. This scientific analysis had evolved during the 1990s and has become "relationship science", through the research done by Ellen Berscheid and Elaine Hatfield. This interdisciplinary science attempts to provide evidence-based conclusions through the use of data analysis.

Patrilineality, also known as the male line, the spear side or agnatic kinship, is a common kinship system in which an individual's family membership derives from and is recorded through their father's lineage. It generally involves the inheritance of property, rights, names, or titles by persons related through male kin. This is sometimes distinguished from cognate kinship, through the mother's lineage, also called the spindle side or the distaff side.

A patriline ("father line") is a person's father, and additional ancestors, as traced only through males.

The veneration of the dead, including one's ancestors, is based on love and respect for the deceased. In some cultures, it is related to beliefs that the dead have a continued existence, and may possess the ability to influence the fortune of the living. Some groups venerate their direct, familial ancestors. Certain religious groups, in particular the Eastern Orthodox Churches, Anglican Church, and Catholic Church venerate saints as intercessors with God; the latter also believes in prayer for departed souls in Purgatory. Other religious groups, consider veneration of the dead to be idolatry and a sin.

In European, Asian, Oceanian, African and Afro-diasporic cultures (which includes but should be distinguished from multiple cultures and Indigenous populations in the Americas who were never influenced by the African Diaspora), the goal of ancestor veneration is to ensure the ancestors' continued well-being and positive disposition towards the living, and sometimes to ask for special favours or assistance. The social or non-religious function of ancestor veneration is to cultivate kinship values, such as filial piety, family loyalty, and continuity of the family lineage. Ancestor veneration occurs in societies with every degree of social, political, and technological complexity, and it remains an important component of various religious practices in modern times.

In biology, offspring are the young creation of living organisms, produced either by sexual or asexual reproduction. Collective offspring may be known as a brood or progeny. This can refer to a set of simultaneous offspring, such as the chicks hatched from one clutch of eggs, or to all offspring produced over time, as with the honeybee. Offspring can occur after mating, artificial insemination, or as a result of cloning.

Human offspring (descendants) are referred to as children; male children are sons and female children are daughters (see Kinship).

Consanguinity (from Latin consanguinitas 'blood relationship') is the characteristic of having a kinship with a relative who is descended from a common ancestor.

Many jurisdictions have laws prohibiting people who are closely related by blood from marrying or having sexual relations with each other. The degree of consanguinity that gives rise to this prohibition varies from place to place. On the other hand, around 20% of the global population lives in areas where some consanguinous marriages are preferred. The degree of relationships are also used to determine heirs of an estate according to statutes that govern intestate succession, which also vary from jurisdiction to jurisdiction. In some communities and time periods, cousin marriage is allowed or even encouraged; in others, it is taboo, and considered to be incest.

In law and in cultural anthropology, affinity is the kinship relationship created or that exists between two people as a result of someone's marriage. It is the relationship each party in the marriage has to the family of the other party in the marriage. It does not cover the marital relationship itself.

Laws, traditions and customs relating to affinity vary considerably, sometimes ceasing with the death of one of the marriage partners through whom affinity is traced, and sometimes with the divorce of the marriage partners. In addition to kinship by marriage, "affinity" can sometimes also include kinship by adoption or a step relationship.

Kinship terminology is the system used in languages to refer to the persons to whom an individual is related through kinship. Different societies classify kinship relations differently and therefore use different systems of kinship terminology; for example, some languages distinguish between consanguine and affinal uncles (i.e. the brothers of one's parents and the husbands of the sisters of one's parents, respectively), whereas others have only one word to refer to both a father and his brothers. Kinship terminologies include the terms of address used in different languages or communities for different relatives and the terms of reference used to identify the relationship of these relatives to ego or to each other.

An uncle is usually defined as a male relative who is a sibling of a parent or married to a sibling of a parent, as well as the parent of the cousins. Uncles who are related by birth are second-degree relatives. The female counterpart of an uncle is an aunt, and the reciprocal relationship is that of a nephew or niece. The word comes from Latin: avunculus, the diminutive of avus (grandfather), and is a family relationship within an extended or immediate family. A popular colloquial term in English is Unc.

In some cultures and families, children may refer to the cousins of their parents as uncle (or aunt). It is also used as a title of respect for older relatives, neighbours, acquaintances, family friends, and even total strangers in some cultures, for example Aboriginal Australian elders. Using the term in this way is a form of fictive kinship.