Psychologist Abraham Maslow formulated a theory of motivation based on humans working to meet their needs. The individual will start with efforts to meet the lowest-level basic needs and as those are met will work up to meeting the highest level of needs. This is the hierarchy of needs often referred to in relation to Maslow’s theory. According to Maslow, a human being will first work to meet basic, biological, or physiological needs, such as food and water. When these needs are met, the individual will next address safety needs, such as shelter and security. After safety needs are met, the person will work toward social needs, such as love and affection. Robert P. Vecchio and other authors have grouped the physiological, safety, and social needs into “deficiency needs,” meaning that they are based on something the person lacks. The upper two sets of needs are called “growth needs” and include esteem and self-actualization. Humans can get by without the growth needs being met, and according to Vecchio, not all people work toward the higher two levels. If social needs have been achieved, the individual will move on to esteem needs, which are based on the view others have of him or her. High or low self-esteem generally comes from feedback received from others. If the esteem needs are met, the person may work toward self-actualization. The concept of self-actualization (self-development and realization) is based on an individual’s reaching his or her potential based on personal expectations. Few humans can reasonably be described as self-actualized, although some individuals may feel this level of satisfaction for a short time based on some major accomplishment. The concept of the hierarchy of needs is often taught to students in MANAGEMENT so they can use it in motivating their employees. If they understand at what level of needs the person is currently operating, the manager will better understand the employee. For instance, an employee may miss work because his or her home has been destroyed in a fire and the family is in need of food and shelter. This prioritization on the employee’s part would be something the manager can understand within the framework of Maslow’s theory. Once the manager learns that the employee has met his or her basic needs, the manager might then be able to come up with appropriate ways to motivate the person as the employee returns to work. Comparisons are often made between Maslow’s hierarchy of needs and the motivational theories of Henry A. Murray, David McClelland, and Frederick Herzberg. According to Vecchio, all are examples of “achievement motivation theory” in that all are based on people motivated by efforts to meet needs. Herzberg’s TWO-FACTOR THEORY OF MOTIVATION is the closest, with hygiene factors and motivator factors roughly corresponding to Maslow’s hierarchy as described by Vecchio. The deficiency needs are the basic needs, or hygiene factors, and the growth needs are the higher-level needs, or motivator factors.