Any list of top CEOs reveals a stunning lack of diversity. Among the leaders of Fortune 500 companies, for example, just 32 are women, three are black, and not one is a black woman. Tony Mayo studied the careers of the roughly 2,300 alumni of African descent who have graduated from Harvard Business School since its founding, focusing on the 67 black women who have attained top positions in corporations or professional services firms. These women thrived, they found, because of three characteristics that are key to resilience. The insights gleaned are essential for any manager who recognizes that an organization’s diversity is its strength.