Stereotypes may arise for a number of reasons.
Explicit stereotypes are those people are willing to verbalize and admit to other individuals.
In social psychology, a stereotype is any thought widely adopted about specific types of individuals or certain ways of behaving intended to represent the entire group of those individuals or behaviors as a whole. These thoughts or beliefs may or may not accurately reflect reality. Within psychology and across other disciplines, different conceptualizations and theories of stereotyping exist, at times sharing commonalities, as well as containing contradictory elements.
The term stereotype comes from the French adjective stéréotype and derives from the Greek words στερεός (stereos), "firm, solid" and τύπος (typos), impression, hence "solid impression on one or more idea/theory."