“A person can perform only from strength,” wrote Peter Drucker. “One cannot build performance on weaknesses.” Yet improving one’s strengths is less straightforward than fixing one’s weaknesses. Doing more of what you already do well will only lead to incremental improvement. A better approach is to improve skills that complement that core strength. How do you identify those skills? John H. Zenger, Joseph Folkman, and Scott K. Edinger studied 250,000 360-degree surveys of 30,000 leaders to identify skill combinations that result in higher performance. In this slideshow, we’ll look at seven core strengths and their complementary skill sets.