Oppositional sexism is the belief that male and female, or masculine and feminine, are two separate and rigid opposing categories, each with their own attributes and characteristics. According to people who ascribe to oppositional sexism, the abilities, traits, and other attributes which are seen as masculine cannot and should not be feminine, and vice-versa.
Julia Serano coined the term oppositional sexism in her first book “Whipping Girl: A Transsexual Woman on Sexism and the Scapegoating of Femininity.” Her new term looked to become an umbrella term for other recognized types of sexism, including cissexism and transphobia.