In our many decades of giving over 10,000 leaders feedback through our Polaris® based assessment centers and 360 surveys, we do occasionally encounter leaders who resist acting on their feedback. For whatever reason, they perceive that they "have arrived" and additional improvements aren't necessary. This often results in arrested development, which is not good for either the leader or the organization. Our attempts to show the benefits of development have included the following points and perspectives:

1. Organizations (and Board of Directors and Customers) expect it! A stagnant leadership team can lead to a stagnant organization. Today's accelerated pace of change in technology, complexity, and global challenges (including sustainability) REQUIRE constant learning. Many autopsies on failed organizations surface the primary cause as static leadership that didn't learn and change quickly enough (think Blockbuster, Kodak, Borders, Sears, Blackberry, etc.). Going through a diagnostic experience like a 360 survey or assessment center, further raises expectations that you WILL try to improve. Even if the survey feedback may be news for you, it's not news to the people who completed the survey and who are probably looking for improvement.
2. Leaders are THE ORGANIZATIONAL ROLE MODELS for learning. It is truly an obligation as a leader to model growth and development. It's difficult to imagine a "learning organization" (an often espoused company goal) without learning leaders. This role modeling is especially important because one of the strongest correlations of culture IS leadership behavior. Therefore, learning about WHAT you are modeling and being deliberate about your behavior is essential to establishing a positive culture.
3. It's good (and desired!) to demonstrate vulnerability as a leader, to show that you don't know it all (and you don't!) and are continuously learning. As Warren Bennis has put it, "Leadership is about RELATIONSHIPS," and trusting relationships are built on transparent communications, which includes admitting liabilities. Often, new leaders feel they must put up an image of invulnerability and a façade of (false?) bravado. This can inhibit learning and can discourage trust. It's OK to show vulnerability.
4. Learning is needed to achieve authentic leadership. There has been much written about being an "authentic" leader. Authenticity and self-objectivity are flip sides of the same coin and receiving feedback (a part of any good development program) improves self-awareness. Acting on that new awareness improves authenticity. As a result, you'll be much happier having learned to lead from a genuine place.
5. You can change! Often there is resistance to leadership development because of pessimism regarding the ability to make personal change. It is true that personality and values probably don't change (short of a truly significant life experience or trauma), BUT mindsets and skillsets CAN and DO change. For example, there are people who have made huge improvements in their effectiveness as leaders through simple changes. At a bank, a commercial lender was rated poorly on a 360 survey for not being communicative about industry trends. This manager went back and made a simple change to put some Google alerts on his computer, filtered through them, and then forwarded some and saved some out to discuss regularly at staff meetings. Two years later he had moved his score up so much that it was on his top ten list. Another example is a manager who was awkward in casual conversations primarily because he just didn't participate. He made a point of actually putting it on his calendar to periodically get up from his desk and walk around the ask people how things were going. Once again, subsequent 360s showed marked improvement.
6. Another more profound reason to continuously grow and develop comes from the research on human motivation. Researchers like Maslow and Alderfer have observed that the ultimate source of happiness is a realization that growth and learning are two of the greatest satisfactions in the human experience. Being a lifelong learner is truly a part of self-actualizing.

Using these as motivators for personal growth as a leader are part of a recipe for successful growth that includes admitting that your aren't perfect, doing a thorough and objective assessment (e.g., Polaris® 360 or assessment center) and limiting your development choices (don't boil the ocean). A final key ingredient - the WIIFM (What's In It For Me) is absolutely essential in motivating yourself over the time it may take to truly change behavior.