The variations in the speech of different groups

There are a number of reasons why these stereotypes exist. One reason is that people often associate certain speech patterns with certain groups of people. For example, the Southern accent is often associated with rural areas and with people who are less educated. This association can lead people to believe that everyone who speaks with a Southern accent is less intelligent or educated, even if this is not the case.

Another reason why these stereotypes exist is that people often equate "proper" speech with intelligence and education. This is because "proper" speech is often associated with the upper classes, who are typically seen as being more intelligent and educated. This association can lead people to believe that everyone who speaks "properly" is intelligent and educated, even if this is not the case.

It is important to remember that there is no one "correct" way to speak English. All dialects are equally valid, and no one should be judged based on their speech patterns. We should all be more accepting of different ways of speaking and try to avoid making assumptions about someone's intelligence or education based on their accent or dialect.

The video you linked is about the different ways that people speak in different parts of the United States. The speaker, linguist John McWhorter, points out that there is no one "correct" way to speak English, and that all dialects are equally valid. However, he also acknowledges that people often make assumptions about someone's intelligence, education, or social class based on their speech patterns.

These preconceived notions are often based on stereotypes and prejudices. For example, people who speak with a Southern accent are sometimes seen as being less intelligent or educated than people who speak with a Northern accent. People who speak with a non-standard dialect may also be seen as being less intelligent or educated, or as being from a lower social class.