Structural violence is a term commonly ascribed to Johan Galtung, which he introduced in the article "Violence, Peace, and Peace Research" (1969). It refers to a form of violence wherein some social structure or social institution may harm people by preventing them from meeting their basic needs. Institutionalized adultism, ageism, classism, elitism, ethnocentrism, nationalism, racism, and sexism are some examples of structural violence as proposed by Galtung. According to Galtung, rather than conveying a physical image, structural violence is an "avoidable impairment of fundamental human needs". As it is avoidable, structural violence is a high cause of premature death and unnecessary disability. Because structural violence affects people differently in various social structures, it is very closely linked to social injustice. Structural violence and direct violence are said to be highly interdependent, including family violence, gender violence, hate crimes, racial violence, police violence, state violence, terrorism, and war.