"Over the course of American history, mainstream culture has adapted a similar aspect of cool" as the West African notion, she said. "There are words that we wouldn't have if Africans hadn't landed on these shores, like 'cool,' 'funky' and 'hip.' "
A more modern twist on cool came about during the first half of the 20th century, through jazz. David Schroeder, the director of jazz studies at New York University, said that cool is intrinsically part of the attitude of jazz musicians, as well as the way that the genre evolved.
"Initially, cool was a term meaning that there was hot jazz — lively and exciting," he said. "Then there was another form that evolved called cool jazz, and cool jazz was more subdued and introverted."
The jazz community expanded the meaning to style, including sunglasses, sharp clothes and sports cars, Schroeder said.
"Musicians still want to act cool and act separate, to follow their own path rather than find the norms of what culture dictates," Schroeder said. "People who have passion to be musicians tend to be more individualistic."
Timothy Parker, who goes by the name Gift of Gab as part of the hip-hop duo Blackalicious, notes that creating music isn't about becoming someone else but becoming the best version of yourself.
"There is a mystique that the music creates, [and] the music kind of takes you to a place where you're more free and you have less inhibitions," he said. "At the same time, I'm still who I am."
Understanding human behavior
Today, cool is an enduring concept that's part of our everyday vernacular. But Dar-Nimrod said there are more profound implications to his research as well.
Harnessing the power of the word and the concept could be used to curb excessive drinking, smoking and poor habits around health and self-image, he adds. "We'd like to see what elements in coolness can be used as a tool to create improvement in people's lives."
Meanwhile, one big question remains.
"The most frustrating thing about this research is that nine years later, we still can't agree on whether Steve Buscemi is cool or not," said Dar-Nimrod. "We have a ways to go before we can give him a coolness quotient."