Heterosexism is a system of attitudes, bias, and discrimination in favor of female–male sexuality and relationships. According to Elizabeth Cramer, it can include the belief that all people are or should be heterosexual and that heterosexual relationships are the only norm and therefore superior. Heterosexism as discrimination ranks gay men, lesbians, bisexuals and other sexual minorities as second-class citizens with regard to various legal and civil rights, economic opportunities, and social equality in many of the world's jurisdictions and societies. It is often related to homophobia.