Microaggression is a term used for commonplace verbal, behavioral or environmental slights, whether intentional or unintentional, that communicate hostile, derogatory, or negative attitudes toward members of marginalized groups. The term was coined by Harvard University psychiatrist Chester M. Pierce in 1970 to describe insults and dismissals which he regularly witnessed non-black Americans inflicting on African Americans. By the early 21st century, use of the term was applied to the casual disparagement of any socially marginalized group, including LGBT people, poor people, and disabled people. Psychologist Derald Wing Sue defines microaggressions as "brief, everyday exchanges that send denigrating messages to certain individuals because of their group membership". In contrast to aggression, in which there is usually an intent to cause harm, persons making microagressive comments may be otherwise well-intentioned and unaware of the potential impact of their words.