Ideology:

A set of beliefs underlying the customs, habits, and practices common to any given social group. To members of that group, the beliefs seem obviously true, natural, and even universally applicable. They may seem just as obviously arbitrary, idiosyncratic, and even false to those who adhere to another ideology. Within a society, several ideologies may coexist; one or more of these may be dominant.

Ideologies may be forcefully imposed or willingly subscribed to. Their component beliefs may be held consciously or unconsciously. In either case . . . [they have been] called “the unexamined ground of our experience.” Ideology governs our perceptions, judgments, and prejudices—our sense of what is acceptable, normal, and deviant.

--from The Bedford Glossary of Critical and Literary Terms