Beautiful and intelligence are highly inconclusive. There are beautiful people who are highly intelligent, even geniuses as there are beautiful people who are of average intelligence. Beauty and intelligence are mutually exclusive. Each are different factors.
However, in many societies as studies have conclusively authenticated repeatedly, beautiful people are considered to be more intelligent than their less attractive counterparts. Beautiful children are considered smarter and more industrious by their teachers. They are also seen as smarter and more apt by their friends and peer group. They exude a positivity which makes teachers and friends respect them more than less attractive children who are considered to be less apt and personable.
Beautiful people also are deemed more intelligent because they take care of themselves more. It is believed that an intelligent person is to be the optimal person mentally, spiritually, psychologically, and especially physically. Even though people refuse to acknowledge that looks matter, they DO matter a lot. People are judged on their looks and more attractive people are considered to be more intelligent because in many people's perception, attractive people are intelligent because they care enough about themselves to put their best foot forward.
Corporations, companies, and industries, especially highly visible industries tend to hire beautiful people because they exude a good image for the former. Beautiful people are draws for companies, corporations, and industries who wish to have the most mass appeal or to draw a better class of clientele. Corporations, companies, and industries also view beautiful people as more intelligent and also more believable when they sell their brand and/or product. Since beautiful people are considered to be more believable by the client and public, they are thus considered to be more intelligent.
Less attractive people sadly are considered to be less intelligent. After all, it is thought that if people do not care enough about themselves or their looks, they MUSTN'T be THAT INTELLIGENT. Especially in this image obsessed culture, intelligent people put their best selves forward by any physical means necessary. If a person does not wish to do that, then he/she must be lazy or lacking otherwise pure and simplpe.