Actually I believe lots of people believe if someone is "good looking" they are NOT smart! or They must somehow be self centered, arrogant, stuck up, bitchy, or narcissistic.
For many decades stereotype words have been used to describe beautiful people such as "bimbo" "airhead", "Ditsy", "trophy wife", "boy-toy", "dumb blonde" "gold digger", "meathead", and so on.
There's an assumption that you can't be both beautiful and smart. Any measure of success you have is because (other people) presumably smart average looking or ugly bent over backwards to get your attention and (give) you whatever you wanted.
They think If you're beautiful there can't be any "substance" to you. There is no "soul". Essentially you're an empty shell.
(Some people actually take pride in rejecting or being rude to beautiful and handsome folks who greet or flirt with them.)
It proves they're not under the beautiful person's "spell".
Society resents beautiful people because they feel life isn't fair!
We ask such as questions as "Would you rather be good looking or smart?" Would you rather be rich or poor with loving friends and family? Would you rather be married to a ....etc?
"Money can't buy you love!"
"Beauty is only skin deep!"
Maybe it's "sour grapes", jealousy, or envy but people can't imagine someone who does "have it all" and is a good person!
In our minds there has to be a "downside" to being good looking or rich. And yet secretly everyone would like see for themselves.