The workshop then takes managers through a series of exercises in which a) they consider why it’s important to understand that people can develop their abilities, b) they think of areas in which they once had low ability but now perform well, c) they write to a struggling protégé about how his or her abilities can be developed, and d) they recall times they have seen people learn to do things they never thought these people could do. In each case, they reflect upon why and how change takes place.

After the workshop, there was a rapid change in how readily the participating managers detected improvement in employee performance, in how willing they were to coach a poor performer, and in the quantity and quality of their coaching suggestions. What’s more, these changes persisted over the six-week period in which they were followed up.

Going from leadership incompetence to leadership competence is not easy, but compelling evidence attests to the efficacy of well-designed, albeit rare, leadership development programs. So, some programs do work. But their effectiveness is built on making leaders aware of their limitations, persuading them to replace their toxic habits with more effective ones, and linking those habits to critical business performance metrics. There are ways of doing it right, and helping leaders improve can make organizations more effective.

Tim Theeboom and his colleagues at the University of Amsterdam published a seminal meta-analysis in this area, reviewing forty-six independent studies on coaching effects. They found that 70 percent of the individuals who were coached could be expected to outperform those who weren’t. Key EQ areas that coaching could improve included coping skills, stress management, and self-regulation, the last of which is a core component of motivation and affects how leaders set and achieve their goals.

Self-awareness, the cornerstone of leadership development, has been valued for thousands of years. The entrance to the temple of Apollo in Delphi was inscribed know thyself. Socrates argued that the essence of his wisdom was to accept his ignorance. Given that people are generally unaware of their limitations, which are exacerbated when they become leaders, leadership development interventions should focus on boosting leaders’ self-awareness. Research suggests that greater self-awareness is a defining feature of high-performing leaders.Accordingly, because good coaching enhances the person’s self-awareness, coaching is often described as systematic feedback.

In sum, bad leaders are unlikely to turn into talented, inspirational, or high-performing leaders. Yes, they can change, but most leaders won’t improve much beyond what you have seen them do in the past, especially if they are left to their own devices. Human inertia makes professional development interventions, such as executive coaching, indispensable, though a much more effective strategy for improving the quality of leaders would be to focus more time, effort, and resources on selecting talented people into leadership roles. As in any other area, prevention is a much better option than treatment, and while there’s no need to choose between one and the other—both should be pursued—leaders will be much more likely to improve when they have been correctly selected.