At 87, Warren Buffett no longer occupies himself with much of the day-to-day business of running Berkshire Hathaway Inc. (BRK.A) Still, the billionaire investor who is hailed as the "Oracle of Omaha" for his investing prowess remains actively involved with the key decisions of the company that he transformed into one of the largest and most successful in the world.

Though he doesn't spend much time interviewing potential candidates for open positions, Buffett prefers now to think of big-picture questions involving the long-term vision for the firm. Still, Buffett's list of criteria by which he judges potential candidates applying for jobs with Berkshire Hathaway has remained steadfast. He revealed three key traits to Nebraska Business magazine.

Intelligence, Energy, and Integrity

"You look for three things: you look for intelligence, you look for energy, and you look for integrity," Buffett indicated in the interview with the alumni publication for the University of Nebraska at Lincoln's College of Business Administration, where he earned a degree.

According to CNBC, Buffett feels that integrity is the most important of these three traits. He explains that "every business student you have has the requisite intelligence and requisite energy. Integrity is not hard-wired into your DNA."

Someone in the business world who does not display integrity may be saddled with a poor reputation as a deceitful individual or as someone who is too self-serving. "A student [of college age] can pretty much decide what kind a person they are going to be at 60," Buffett explains. "If they don't have integrity [now], they never will. The chains of habit are sometimes too heavy to be broken. Students can forge their own chains."

Finding a Role Model

Going along with these principles for finding an employee, Buffett also shared his method for seeking out a strong role model to look up to. "Just pick a person to admire and ask why you admire them," he said. "Usually it is because they are generous, decent, kind people, and those are the kind of people to emulate."

According to CNBC, experts on workplace interactions support Buffett's claim. Studies have shown that seeking out an appropriate mentor can aid you in developing your career and professional life. Mentors can also help individuals become more productive, gain critical thinking skills, and become more resilient in the face of struggles.

For Buffett, the tide has likely turned, as the billionaire is sure to be the focus of many younger investors looking for role models of their own. And while the tenets of intelligence, energy, and integrity likely hold true as valuable traits in employees across a range of industries, his own role in crafting Berkshire Hathaway into the behemoth that it is today cannot be understated. (See more: How Warren Buffett Made Berkshire Hathaway.)