Heteronormativity: The belief is that people fall into distinct and complementary genders (man and women) with natural roles in life.
It assumes the heterosexuality is the only sexual orientation or only norm and states that sexual and marital relations are most fining between people of the opposite sex. Heteronormativity is an assumption that all people are straight and only a normal and natural expression of sexuality
What constitutes appropriate behaviour for girls/women and boys/men is a result of social conditioning, indoctrination, and cultural definitions. Hence, there is variability between societies, as well as within groups in a specific society. This leads us to understand the dominance of ‘heteronormativity’ (that is the norm that reinforces and ‘normalizes’ the gender binary) in society and in all its institutions such as family, marriage, polity, economy, religion, etc.
Example: Marriage between men and women gives them social recognition and support for an intimate relationship i.e., socially and legally approved in our society.