Its validity is proven just by watching people. D Some people are forceful, direct and results oriented. It represents how people respond to problems and challenges. Some people are optimistic, fun and talkative. It represents how you influence others to your point of view.
Some people are steady, patient and relaxed.
Steady - Consistency. It represents how you respond to the pace of the environment. Some people are precise, accurate and detail oriented. Compliance - Constraints. It represents how you respond to rules and procedures set by others.