Mark Twain once said it's better to keep your mouth shut and be thought a fool than to open it and remove all doubt.

That's a good line -- but it's wrong, according to recent research that shows people judge strangers' intelligence in some odd ways.

However, you can take advantage of such stereotypes. Tom Cutler, author of "211 Things a Bright Boy Can Do," has recommendations based on the findings to ensure you always look like a genius.

Quick Tips to Make You Look Smart