A "military brat" (an various brat derivatives) is a term for a person whose parent or parents have served full-time in the armed forces during the person's childhood. In conventional usage, the word "brat" used alone may be derogatory; in modern, especially American usage, however, "military brat" is often not considered to be a derogatory term (and may in fact be seen as a term of endearment). Although the term is used in other English-speaking countries, it is exclusively in the United States that this term is ascribed to a collectively identifiable demographic (with extensive psychological research done on the group by U.S. Defense Department). Accordingly, this group is shaped by frequent moves, absence of a parent, authoritarian family dynamics, strong patriarchal authority, threat of parental loss in war, and a militarized family unit. While non-military families share many of these same attributes, military culture is unique due to the tightly knit communities that perceive these traits as normal. Although they did not choose to belong to it, military culture can have a long-term impact on brats.