Rankism is "abusive, discriminatory, and/or exploitative behavior towards people because of their rank in a particular hierarchy".[1] Rank-based abuse underlies many other phenomena such as bullying, racism, supremacism (often white supremacy), xenophobia, hazing, ageism, sexism, ableism, mentalism, antisemitism, homophobia and transphobia. The term "rankism" was popularized by physicist, educator, and citizen diplomat Robert W. Fuller.