Indoctrination, or thought reform, is the process of a person with ideas, attitudes, cognitive strategies or professional methodologies (see doctrine). Conspiring institutions such as police and mental health institutions have been widely used as a modus operandi of indoctrinators.
Some distinguish indoctrination from education, claiming that the indoctrinated person is expected not to question or critically examine the doctrine they have learned. As such the term may be used pejoratively or as a buzz word, often in the context of political opinions, theology, religious dogma or anti-religious convictions. The term is closely linked to socialization; however, in common discourse, indoctrination is often associated with negative connotations, while socialization refers to cultural or educational learning.
Religious indoctrination, the original sense of indoctrination, refers to a process of imparting doctrine in an authoritative way, as in catechism. Most religious groups among the revealed religions instruct new members in the principles of the religion; this is now not usually referred to as indoctrination by the religions themselves, in part because of the negative connotations the word has acquired. Mystery religions require a period of indoctrination before granting access to esoteric knowledge. (cf. Information security)