HQ vs. IQ

According to this article, being smart doesn't necessarily mean you will be happier:

"Researchers found happiness in old age was not associated with lifelong intelligence in a group of healthy men and women living in Scotland."

I'm not sure why it took a study to determine this fact. But the opposite must be true as well. Being dumb doesn't make you happy either. So if the choice is dumb and miserable OR smart and miserable, I think the latter would be preferable.