Hedge-fund billionaire Ray Dalio asked Bill Gates, Elon Musk, Reed Hastings and other top leaders to take a 1-hour personality test - and they all scored low in one key area

Heidi Gutman / CNBC

Bridgewater Associates founder Ray Dalio.

• Bridgewater Associates founder Ray Dalio gave a 1-hour personality test to today's biggest innovators: Elon Musk, Bill Gates, Reed Hastings, and others.
• They did well when it came to being assertive, open-minded, and having a big vision for their companies.
• They all scored low in one key category: "Concern for others."
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What does it take to be a titan of industry? Independent thinking, resiliency, and passion - and apparently, not letting someone's upset feelings get in the way of achieving a vision.

This was a lesson hedge-fund billionaire Ray Dalio spotted after giving a one-hour personality test to top tech leaders like Jeff Bezos, Elon Musk, and Bill Gates, who all scored poorly in the "Concern for Others" category.

The anecdote comes from Dalio's best-selling book, "Principles." In 2011, Dalio was beginning a seven-year transition out of his founder-leader role at Bridgewater Associates, currently the world's largest hedge-fund with $150 billion in assets under management. He writes that there was a vacuum left after his departure, which he called the "Ray gap." He was worried that his company would flounder without him. To find out exactly what was missing from Bridgewater in his absence, he sent out a test to other CEOs and company founders to find their defining qualities.

The test closely followed the Bridgewater personality test that Dalio administers to potential new hires, which is in turn based on the Myers-Briggs Type Indicator (MBTI). Dalio has told Business Insider, "We look for people with a wide range of thinking types." It may take all sorts to work in a company, but Dalio found that leaders aren't that different from one another.

Dalio called these business giants "shapers," or people who shape society. According to him, there are two types of shapers: managers and inventors. Managers take a great idea and perfect it without much creative thinking, while inventors push their vision without necessarily turning it into a business. For example, Albert Einstein was an inventor. Jack Welch (GE) is a manager. Bill Gates and Elon Musk are both, as was Steve Jobs.

The test was given to shapers like Elon Musk (Tesla, SpaceX), Bill Gates (Microsoft), Jack Dorsey (Twitter), Jeff Bezos (Amazon), and Reed Hastings (Netflix). When they were faced with the choice between achieving their goals or pleasing others, they chose to achieve their goals every time.

However, Dalio goes on to say that scoring low in this category doesn't mean what most people think. It means that, when given the choice of caring about pursuing a vision or upsetting someone, these leaders will choose to overlook upsetting someone to get whatever needs to be done.

So, they're not really heartless: They just won't let anything stand in their way, including some hurt feelings.

Shapers did have some other qualities in common as well: the ability to pay attention to the big picture and the details at the same time, not letting anyone stand in the way of their goals, and having a flexible vision that changes in order to make things work better.