Finally, we know what it means to be "cool." (And it probably begins with me not tying "cool" in quotations.)
According to a study by the Journal of Consumer Research (and broken down for us non-scholastic folk by The Atlantic), the theory of "cool" is comparable to that of humour: the Superiority Theory — a.k.a the fact that we laugh at things that make us feel and seem superior.
BUT that obviously doesn't apply to all jokes, and like jokes, coolness is also undefinable — in a way. As defined in a paper by Caleb Warren and Margaret C. Campbell, "Coolness is a subjective, positive trait perceived in people, brands, products, and trends that are autonomous in an appropriate way."
In the words of Atlantic writer Derek Thompson, "cool is a measured violation of malign expectations." So: being cool means being a rebel (in a way).
"Cool means departing from norms that we consider unnecessary, illegitimate, or repressive — but also doing so in ways that are bounded," Thompson writes. "The 1984 Apple ad that said, essentially, 'You have a choice; don't buy IBM!" was considered one of the coolest commercials of all time, becaue it was, in the researchers words, 'autonoumous in an appropriate way.'"
"But an Apple ad saying, 'You have a choice; don't pay federal income taxes!' wouldn't be cool, because taxes are legitimate," he continues. "And a 1984 Apple ad saying 'Burn IBM's headquarters to the ground!' wouldn't be cool because that's just overdoing it. Cool requires a bit of Goldilocks."
So applied to say, trends, crop talks are "cool" because they challenge typical and safe style conventions. On the flipside, wearing only a bandeau to work would be less so because a dress code is legitimate. (You usually agree to one when you begin working someplace.) Meanwhile, not wearing a top at all would be overdoing it, too — and for what?
There needs to be something to rebel against — enter: normcore, and its rebellion against alternative fashion. But odds are you still won't see a sweatsuit at fashion week because it's taking the trend too far. You also won't see a onesie pajama set. Basically, cool is just rebelling enough. A fine balance. Yet nothing like the book by the same title.