Twenty-four hundred years ago, scientists and philosophers, most notably Hippocrates, began to recognize and categorize differences in behavior that seemed to follow a pattern.

Since then, many psychologists and scientists have explored behavioral patterns. Dr. William Marston wrote “The Emotions of Normal People” in 1928 after earning his doctorate from Harvard University. Marston theorized that people are motivated by four intrinsic drives that direct behavioral patterns. He used four descriptive characteristics for behavioral tendencies which are represented by four letters of the alphabet: D, I, S and C. Thus the concept of “DISC” was introduced.