"Lost boys" is a term used for young men who have been excommunicated or pressured to leave polygamous Mormon fundamentalist groups, such as the Fundamentalist Church of Jesus Christ of Latter Day Saints (FLDS). Although sometimes officially accused of apostasy or disobedience, it is thought that they are mainly pressured to leave by older adult men to reduce competition for wives within such sects, usually when they are between the ages of 13 and 21.