In the present contribution, the author investigated the idea that messages communicating inclusion by others lead to stronger conspiracy beliefs about impactful societal events than messages communicating exclusion by others. These effects of belongingness, however, were expected only among people who experience high levels of self‐uncertainty. In Study 1, a manipulation of belongingness predicted belief in conspiracy theories only among people with unstable self‐esteem (an individual difference indicator of self‐uncertainty), while controlling for self‐esteem level. In Study 2, a manipulation of belongingness influenced belief in conspiracy theories only among participants who were experimentally induced to feel uncertain about themselves. It is concluded that among self‐uncertain people, inclusion breeds suspicion about the causes of impactful and harmful societal events.