Personality and aptitude tests (psychometrics) are helpful for managing people and for understanding yourself. You should also consider using personality and aptitude tests if you are recruiting or developing people.
Each of us is motivated by needs. Our most basic needs are inborn, having evolved over tens of thousands of years. Abraham Maslow's Hierarchy of Needs helps to explain how these needs motivate us all. Maslow's Hierarchy of Needs states that we must satisfy each need in turn, starting with the first, which deals with the most obvious needs for survival itself. Only when the lower order needs of physical and emotional well-being are satisfied are we concerned with the higher order needs of influence and personal development.