21st century leaders will be growers, not knowers.

The most damaging cognitive bias is overconfidence (illusory superiority), making leaders use their “gut” when they should be more rational.

There was nothing scientific about Scientific Management (Taylorism), and neither was it good management.

Many of the cataclysmic leadership failures were failures of rationality. The pendulum of leadership development needs to swing back toward the rational: strategy, creativity, foresight, decision-making, and analytics.

Leaders need to sacrifice "power-over" to get "power-to".

Although science is not easy in complex human systems, we cannot afford to throw our hands in the air and give up. It may take decades, but it is a game worth playing and winning.