Ilan Dar-Nimrod, lead author of the study "Coolness: An Empirical Investigation," measures it:
"James Dean is no longer the epitome of cool," Dar-Nimrod said. "The much darker version of what coolness is still there, but it is not the main focus. The main thing is: Do I like this person? Is this person nice to people, attractive, confident and successful? That’s cool today, at least among young mainstream individuals." …
"I got my first sunglasses when I was about 13," said Dar-Nimrod. "There wasn’t a cooler kid on the block for the next few days. I was looking cool because I was distant from people. My emotions were not something they could read. I put a filter between me and everyone else. That, in my mind, made me cool. Today, that doesn’t seem to be supported. If anything, sociability is considered to be cool, being nice is considered to be cool. And in an oxymoron, being passionate is considered to be cool—at least, it is part of the dominant perception of what coolness is. How can you combine the idea of cool—emotionally controlled and distant—with passionate?"
The Dish 