Stereotypes

Origin
The term “stereotype” was taken from the Greek words στερεός (stereos), "firm, solid" and τύπος (typos), "impression ", thus "solid impression".
The term comes from the printing trade and was first adopted in 1798 by Firmin Didot to describe a printing plate that duplicated any typography. The duplicate printing plate, or the stereotype, is used for printing instead of the original.

The term “stereotype” was taken from the Greek words στερεός (stereos), "firm, solid" and τύπος (typos), "impression ", thus "solid impression".
Outside of printing, the first mention of "stereotype" was in 1850, as a noun that meant "image perpetuated without change." However, it was not until 1922.
The "stereotype" was first used in the modern psychological sense by American journalist Walter Lippmann in his work ”Public Opinion”.
In social psychology, a stereotype is a thought that can be adopted about specific types of persons or certain ways of doing things. These thoughts or beliefs may or may not accurately reflect reality.
Origin

Age stereotypes
In some cultures age is a virtue, while in others it may seem to be a curse. We all find that as we get older, certain things are expected of us. Many older people feel themselves discriminated against in areas such as work, housing and sports. With the average age of populations around the world increasing and health care improving, many countries are finding that the expectations and laws regarding age need to be reconsidered.

Ethnic stereotypes
An ethnic stereotype is a system of beliefs about typical characteristics of members of a given ethnic group or nationality, their status, society and cultural norms. National stereotypes may be either about their own nationality or about others. Stereotypes about their own nation may aid in maintaining the national identity.
Various anti-national phobias and prejudices operate with ethnic stereotypes.

Gender stereotypes
The age-old battle of the sexes is a major subject under diversity. Equality between the sexes is still relatively new concept in some societies (women did not have the right to vote in the United States until 1920). Stereotyping is a form of prejudice and many people stereotype what is expected of a woman and what is expected of a man.

In many countries around the world the dominant culture sets the standards and norms for day-to-day living. People who are not part the dominant culture find themselves stereotyped and victims of prejudice when it comes to jobs, educational opportunities, housing, and so forth.

Religious stereotypes
Religious stereotyping is the act of discrimination against members of other religions and is commonly based on generalised ideas and appearances of other religious beliefs and practices. It is important to understand that religious stereotypes, as well as many other stereotypes, are misleading and that one cannot judge a person by their religious background.

If you don’t like or don’t trust somebody because of stereotypes, you have a prejudice against that person (or group of person). It is dangerous because it leads to discrimination and conflicts.