Building on our study findings that CEOs who lead through influence were the most effective, we followed up by conducting interviews to learn about the development advice and training these leaders had received. We asked leaders to describe how they made the journey to becoming the highly effective leaders they were. What emerged is that a leader’s evolution generally proceeds in iterative cycles, with steps forward often followed by backsliding into old habits and then a renewed effort at change. It’s a process of trial and error, and often of fits and starts, as the daily grind of immediate demands diverts attention from one’s inner work. Those who continue to progress in the journey typically go through a three-phase cycle.

First, they are confronted with a necessity for change either because they took on a new challenge that reveals the shortfalls in their leadership or through feedback from their higher-up, colleagues, or mentor.

The study analyzed the fortunes of nearly four hundred CEOs appointed to the helm of S&P 500 companies within the decade of 2004 to 2014. A set of the fifteen most effective early moves was identified. And out of those, the highest performers relied most on these five: operational improvements, launching new products, improving customer relationships, increasing employee engagement, and culture change.

Opinion about the high-engagement PE model is not universally positive. Some criticize the intense involvement of PE firms for turning the CEO into more of a “COO plus.” In this view, PE firms are primarily interested in hiring executives great at execution, who will put strong emphasis on operational improvements. They aren’t looking for input— or not much— into the strategy for growth, and they curtail CEO power.

In all cases, an essential truth is that the CEO is still the one primarily in charge of running the company. The PE firm provides an idealized model of the transformation process, and the CEO brings the wisdom of experience in how to actually manage the messier, human process of execution.

In the past, primary emphasis was placed on financial and operations acumen— still, obviously, important— but today the vanguard of innovators in the sector increasingly appreciate a CEO’s people leadership skills for achieving the above-market returns investors expect.