I love being exposed to new ideas. Sometimes they’re challenging or even scary to contemplate, but always, whole new worlds are revealed. I don’t want to miss out on that, so I’m alert for habits that can limit my ability to think well. 
Clifford Nass, a professor of communication at Stanford University was quoted in the New York Times as saying “We tend to see people who say negative things as smarter than those who are positive. If I tell you that you are going to give a lecture before smarter people, you will say more negative things.”
Notice Professor Nass doesn’t say that negative people are actually smarter, just that we tend to think they are.
A well-thought-out argument and lively debate are excellent ways to sharpen your intellect and ability to think critically. But critical thinking doesn’t mean one has to be negative. I can certainly give a reasoned argument that’s positive.
Being constantly negative and critical, especially if it’s done simply to try and impress others (or yourself – yikes!) with your intelligence, is a surefire way to limit your ability to see what’s good and working. It’s also a mental habit that diminishes happiness. No smart person would do that to themselves.
The Pink Elephant Room 