The No. 1 trait that sets highly successful people apart, says Harvard expert: 'It's rare to find'

Harvard Business School professor Joseph Fuller has spent the better part of a decade studying — and working with — some of the world's most successful people, from Fortune 500 executives to Nobel Prize laureates. 

What sets high achievers apart from everyone else, Fuller has discovered, isn't their confidence or business acumen — it's their adaptability.

"They're not wedded to some predetermined career path that they set when they were a student or starting their first job," he tells CNBC Make It. "They're open to unexpected opportunities and embrace change instead of fearing it."

It's great to set career goals and create timelines for achieving them. The danger, Fuller says, is leaning so hard into your preferences that you become closed off to a sudden detour or nonlinear path.

For example: You might turn down a job at a small startup that excites you and pays well because you always planned to work for a large, well-known company. 

Or, you might be tempted to look for a new job — even if you're content in your current role — because you're not getting promoted as quickly as you thought you would. 

In both cases, "you're ignoring what motivates or interests you, and instead letting rigid expectations guide your career," says Fuller. "That type of stubborn mentality won't take you far."

If you fixate on a specific career path, you risk overlooking other fulfilling options for your professional life, Fuller adds. 

Adaptability is a soft skill that's "increasingly in demand" across a wide range of industries, according to recent research from LinkedIn. 

The need for flexible, resilient employees in the workplace, LinkedIn found, is the direct result of changes to the post-pandemic workforce: the rise of AI, the widespread