Fictive kinship is seen by most current anthropologists as working alongside (or within) but not replacing traditional kinship.
Janet Carsten developed the idea of "relatedness" in response to David M. Schneider's 1984 work on Symbolic Kinship (A Critique of The Study of Kinship). Carsten developed her initial ideas from studies with the Malays in looking at what was socialized and biological. Here she uses the idea of relatedness to move away from a pre-constructed analytics opposition which exists in anthropological thought between the biological and the social (1995, The substance of kinship and the heat of the hearth; feeding, personhood and relatedness among the Malays in Pulau Langkawi, American Ethnologist). Carsten argued that relatedness should be described in terms of indigenous statements and practices, some of which fall outside what anthropologists have conventionally understood as kinship (Cultures of Relatedness, 2000).
A noted Gurung tradition is the institution of "Rodi" where teenagers form fictive kinship bonds and become Rodi members to socialize, perform communal tasks, and find marriage partners.
In Western culture, a person may refer to close friends of one's parents as "aunt" or "uncle" (and their children as "cousin"), or may refer to close friends as "brother" or "sister". In particular, college fraternities and sororities usually use "brother" and "sister" to refer to members of the organization.
The term has such a broad usage as to suggest that it might be spurious. Compadrazgo, common membership in a unilineal descent group, and legal adoption are among the phenomena which are described as examples of fictive kinship. An alternative standpoint would be that "either you're related or you aren't".
Fictive kinship was discussed by Jenny White in her work on female migrant workers in Istanbul (Money Makes Us Relatives, 1995). In her work she draws on ideas of production and the women she works with being drawn together through 'webs of indebtedness' through which the women refer to each other as kin.