Guy Raz has interviewed some of the most influential business leaders of today: Over the past three years, the host of NPR's "How I Built This" podcast has sat down with Spanx founder Sara Blakely, serial entrepreneur Richard Branson and Zappos CEO Tony Hsieh, among others.
The key to their success isn't just work ethic and resiliency, Raz found. Successful entrepreneurs share "an incredibly underrated quality," Raz tells CNBC Make It: They're nice.
"Virtually all the people we've had on the show are kind," he says. "They are respectful and they value and show appreciation for the people who work around them."
It's a quality that goes a long way: "The return on the investment in kindness is enormous. If you run a kind company and you're a kind entrepreneur and you're collaborative, you will retain your employees. You will find that people will work so hard to innovate for you and your ideas."
Billionaire Mark Cuban, who owns the Dallas Mavericks and is a judge on ABC's "Shark Tank," agrees. "One of the most underrated skills in business right now is being nice. Nice sells," he told Vanity Fair in a 2018 interview.
It's a lesson the 61-year-old has learned over his lengthy career. "I wouldn't have wanted to do business with me when I was in my 20s," admitted Cuban, who started his first company, MicroSolutions, after being fired from a computer software company in his 20s. "Early on in my career, I was like bam, bam, bam, bam, bam — I might curse. I might get mad. I had to change, and I did, and it really paid off."
Similarly, studies show that emotional intelligence, or EQ, can make you wealthy and successful. People with high levels of EQ tend to be self-aware, socially aware, empathetic and open to feedback.
Ultimately, it's your ability to cooperate with others that will make you valuable in the work force, global career development expert Soulaima Gourani tells CNBC Make It: "A lot of jobs are going to disappear, but the thing that we will always have that is more important is your emotional intelligence." She defines that as having a "good understanding of yourself, self-control, empathy and a natural understanding of people's decisions, needs and desires."
Those skills can go a long way. "If you can handle people's diversity — people of a different age, different personalities, or educational backgrounds, for example — and you can handle the conflict that comes with that, you will be the highest-paid, most valuable employee in the company," she adds.
It's no coincidence that the successful CEOs and business owners that Raz has talked to actively practice kindness. It's "one of their secret weapons," he says. "They really do think about how to be kind."
Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank."
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