Defining what makes a great leader is risky business. Leaders come in all shapes and sizes. Some shuffle about in flip-flops and others are dressed in crisply pressed, impeccably tailored suits. Some speak softly and some tread heavily. How can a person possibly, then, outline what it takes to be an effective leader? Well, rather than look at the differences between leaders like Nelson Mandela, Malala Yousafzai, Warren Buffet, or Gabrielle Giffords, examine what these exceptional people all have in common.