He's dumber than a bag of rocks! (Mankind)

If you believe that tax policy has nothing to do with the economy, then you're pretty much like a rock, only dumber.

— John Kennedy

The dumber people are, the more they feel the need for a broad set of shoulders they can lay their head against.

— Michael Haneke

Just when I thought you couldn't get any dumber, you go and do something like this... and totally redeem yourself!

— Harry Dunn

I feel like the world is getting dumber. I don't necessarily think people are stupid, but I think we're getting dumber.

— J.I.D

Mike looks even dumber than he normally looks.

— Pauly D

The dumbing down of the country reflects itself on Broadway. The shows get dumber, and the public gets used to them.

— Stephen Sondheim

One of my favorite films is 'Dumb and Dumber.'

— Paul Dano

Human beings are about 1,000 times dumber and meaner than they think they are.

— Kurt Vonnegut

While he was not dumber than an ox, he was not any smarter either.

— James Thurber

“The human brain is actually dumber than you think it is”

— Sohn Won-Pyung

“They never learn. The smarter they are, the dumber they get.”

— Dean Koontz

The dumber half of the audience - whether they're male or female, and a lot of them are male - for some reason responds…

— Frank Black

You go to school everyday. Folks who think they've learned everything they need to know are usually dumber than chickens.

— Jodi Thomas

I'm better than your next man and if you're swingin' like you're dumber than the next man.

— The Weeknd

I've actually become much, much dumber through being married and having these children. I find that I'm not half as sharp that I once…

— Patrick Warburton