Motivation is the process that accounts for an individual's intensity, direction, and persistence of effort toward attaining a goal. Early theories include Maslow's hierarchy of needs, McGregor's Theory X and Y, Herzberg's two-factor theory, and McClelland's theory of needs. Contemporary theories discussed include self-determination theory, job engagement theory, goal-setting theory, self-efficacy theory, reinforcement theory, equity theory, and expectancy theory. Each theory provides a different perspective on factors that influence human motivation.