For two out of three CEOs in our database, performance was lower in their years six to ten than it was in years one to five. Some gave up their gains of the first five years altogether. Results may not actually dive into negative territory, but if they do, they vacillate up and down around a mean, which only reinforces the sense that one can let up on the gas.

The danger is exacerbated when boards also become less energetic in pushing for vigorous changes in strategy or operations. As director Ann Hanley shared, “It’s easy to get into incremental mode.” A CEOs internal team may resist a continuous quick pace of change.

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.

Much less focus, however, has been put on the problem of more gradual deterioration, or stagnation, of performance. Our Life Cycle research reveals that this is a particularly common development beginning approximately after the first five years of a CEO’s tenure. Company performance was lower on many fronts in years six to ten for two out of three CEOs than in their first five years. The rate of revenue increase slowed in these later years. Both EBITDA and ROIC slackened relative to earlier years, companies often became less efficient, and growth in operating income stalled.

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.

Improving the performance of companies that are performing fairly well is now the predominant objective, and PE firms have learned that a CEO’s people leadership abilities are the vital complement to strength in finance and operations for this new frontier of performance improvement.