Have you noticed that you “click” better with some people than with others? The problem is, we treat—and work with—a broad variety of people. Even the venerable Hippocrates observed that his patients reflected four different “personas,” with each persona taking a particular view of the world that heavily influenced their preferred responses and behaviors. The famed Greek physician noticed that each style benefitted from a different approach to best engage in the most effective treatment. While his description of them is understandably dated, the validity and general meaning of his observations have been reliably noticed in the studies of human nature ever since.