Eileen Vartan Barker is a professor in sociology, an emeritus member of the London School of Economics (LSE), and a consultant to that institution's Centre for the Study of Human Rights. She is the chairperson and founder of the Information Network Focus on Religious Movements (INFORM) and has written studies about cults and new religious movements.

A cult is a group which is typically led by a charismatic and self-appointed leader, who tightly controls its members, requiring unwavering devotion to a set of beliefs and practices which are considered deviant. It is in most contexts a pejorative term, also used for a new religious movement or other social group which is defined by its unusual religious, spiritual, or philosophical beliefs and rituals, or its common interest in a particular person, object, or goal. This sense of the term is weakly defined – having divergent definitions both in popular culture and academia – and has also been an ongoing source of contention among scholars across several fields of study.