They think beautiful people are intellectual
Some people feel that beautiful people are more intelligent than people who are less attractive because of the attractiveness halo effect. While some studies have proven that this psychology is correct while some of the reviews assail.
If you are looking good, you are reflecting good health
According to some scientists, if people are looking good, it signifies that they are healthy.
People assume that they have good traits
Some people are too much bothered about their looks as they think that they will be considered to have ample of good qualities only when they are looking good. Also, some psychologists have said that symmetrical faces are better for the efficient functioning of the brain.
They want to look younger
Attractive people often look younger than the person who is not good-looking. Due to which they care extensively about their looks.
Symmetrical Faces are more accessible for the brain to process
Some people think this way; the mind finds it more comfortable to process thoughts with the faces in good shape. (See Why do we like familiarity?)
The media effect
Some people are often highlighted in media, maybe because they are a celebrity or they are a renowned personality. For those people, looks is the primary concern.
People feel confident when other people see them
Some people think that if they look good, those who will see their faces while talking will feel better because of the good personality traits they get reminded of.
According to some men, women look to reflect their levels of fertility. So, some women are very much concerned about their looks to showcase men that they look good and are more fertile. (See What makes female face attractive?)
They reflect status
Some people think that if they look less attractive, they may not reflect good status because many men are attracted to charming women in the first place, thinking that whenever they get married, they will have a graceful child.
Symmetrical faces will reflect good genetics and be considered to have better immunity and the ability to combat diseases.