Those lists in business publications about “best companies to work for” are eminently browsable to see who made the cut–and who’s notably absent. But Michael O’Malley and Bill Baker, authors of Organizations for People: Caring Cultures, Basic Needs, and Better Lives, decided to take a much deeper look, putting 21 of the consistent performers on those lists under a microscope.

Visiting a diverse selection of companies including Patagonia, The Motley Fool, and Edmunds.com, they interviewed executives, conducted focus groups, and toured facilities. In a recent piece in Harvard Business Review, O’Malley summarized their findings. Here are some of the things the authors believe these companies do differently from their peers–and why they’re successful:

Put People First

“The best places to work provide people with life satisfaction as opposed to job satisfaction alone. Almost all of the corporate founders and CEOs we spoke with told us that they built their companies with people in mind. To them, a healthy culture is as important as a healthy balance sheet. Their benefits go far beyond minimum wage,” O’Malley wrote.

Help Workers Find and Pursue Their Passions

“The companies we studied find ways to rejuvenate employees by helping them identify their ‘calling,’ or the area of work that provides them with the greatest fulfillment,” O’Malley wrote. “Doing so not only increases productivity, it makes people feel happy—lucky even—to be at work. … The surest way to improve performance is to give people something they like doing.”

Bring People Together on a Personal Level

“Before beginning this project, we considered life events, rituals, and rites of passage—such as marriages, birthdays, and anniversaries—as trivial to the work environment. But the companies we visited gave us a new perspective. In fact, they made a big deal out of significant dates. Why? These social extracurriculars may appear contrary to real work, and to some, as senseless wastes of time. But forming meaningful relationships is real work. The best companies realize that personal affinities and deep social bonds are failsafe measures against team breakdowns and are essential for top team performance,” wrote O’Malley.

Empower People to Own Their Work

“The executives we interviewed repeatedly told us that they want their employees to think and act like owners. Allowing them to control aspects of their work, we learned, is the key to accomplishing this. Employees who have the leeway to rearrange, modify, and improve their assignments feel possession over them, and once this happens, their mindsets begin to change,” wrote O’Malley. “Instead of focusing on what cannot be done, they become preoccupied with what can. As a result, they are more easily able to grow, innovate, and push their companies forward.”