The belief that one age category is by nature superior to that of another age category.

Ageism

Explanation:

It's exactly what it sounds like.

Ageism is a type of discrimination or stereotyping against people because of their age. Usually this term is applied to the discrimination of older people.

There are several ways that ageism can affect people. For example, an older person may not be hired for a job, because they may be seen as being close to retirement or not technologically savvy.

Another common ways that ageism can affect people is how older people (or younger people) are perceived. Older people can be stereotyped as feeble, forgetful, or slow. Younger people can be characterized as rude, disrespectful, or irresponsible, due to their age.

Although this may be the case for certain individuals, these labels cannot be applied to a whole group of individuals, due to their age bracket.