Full context:   Family, gender and sexuality form a broad area of inquiry studied in many sub-fields of sociology. A family is a group of people who are related by kinship ties :- Relations of blood / marriage / civil partnership or adoption. The family unit is one of the most important social institutions found in some form in nearly all known societies. It is the basic unit of social organization and plays a key role in socializing children into the culture of their society. The sociology of the family examines the family, as an institution and unit of socialization, with special concern for the comparatively modern historical emergence of the nuclear family and its distinct gender roles. The notion of "childhood" is also significant. As one of the more basic institutions to which one may apply sociological perspectives, the sociology of the family is a common component on introductory academic curricula. Feminist sociology, on the other hand, is a normative sub-field that observes and critiques the cultural categories of gender and sexuality, particularly with respect to power and inequality. The primary concern of feminist theory is the patriarchy and the systematic oppression of women apparent in many societies, both at the level of small-scale interaction and in terms of the broader social structure. Feminist sociology also analyses how gender interlocks with race and class to produce and perpetuate social inequalities. "How to account for the differences in definitions of femininity and masculinity and in sex role across different societies and historical periods" is also a concern.