When should your organization start training its employees for leadership roles? That’s a trick question. It can be answered by asking: Why hasn’t it started?

According to a study by the leadership development organization Zenger Folkman, organizations are waiting too long to help millennials develop leadership skills. After analyzing 17,000 leaders, Jack Zenger found that the average trainee is 42 years old, which means he or she has spent a good decade in the industry acting on instinct instead of formal training. “The fact that so many of your managers are practicing leadership without training should alarm you,” Zenger wrote in Harvard Business Review.

According to the U.S. Bureau of Labor Statistics, Gen Y employees, often referred to as millennials, will make up 40 percent of the U.S. workforce by 2020. The Gen Y group are often described as results-driven and self-starters to begin with, and  organizations could leverage those characteristics. But Zenger notes, “Today we are devoting roughly three-fourths of our development effort to Gen X and 20 percent on Gen Y.”

Some organizations fear losing Gen Y employees, since they’ve been known to hop around from job to job. Ninety-one percent of millennials expect to stay in a job for three years or less, according to the Future Workplace “Multiple Generations @ Work” survey. Zenger’s theory: The sooner organizations train Gen Y employees, the more time they will have in the workforce to develop as leaders, and they will find success earlier in their careers.

J. Maureen Henderson, a Forbes contributor who writes about early career issues, would probably agree with Zenger’s theory. “If your company has a strong commitment to supporting the professional development of its employees, clear opportunities for internal advancement, and a track record of promoting from within, you have nothing to fear when millennials ask, ‘What’s in it for me?'” she writes in her article, “Why Managing A Millennial Is Easier Than Training A Dog.”

Zenger thinks putting a leader in place without training should put you on edge: It allows room for mistakes and bad habits. “It may be possible to teach old dogs new tricks, but there’s no question that the sooner you begin, the easier it is,” he writes.

How does your organization handle leadership development?

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