That is a rationalization for drinking beer. I'm not against alcohol, but I am against people deceiving themselves about its effects. Alcohol will make you less, not more intelligent.
It's a joke on a sitcom. Not meant to be taken at face value.
In defense of your comment, a lot of younger alcoholics think it is funny because they want it to be true.
#ThatsTheJoke
Except it's not always true. A little bit of alcohol can take the edge off, reduce the stress. I don't know about you, but I myself am like 20 IQ points dumber when stressed out.