Positive psychology is the scientific study of what makes life most worth living, focusing on both individual and societal well-being. It studies "positive subjective experience, positive individual traits, and positive institutions...it aims to improve quality of life." It is a field of study that has been growing steadily throughout the years as individuals and researchers look for common ground on better well-being.Positive psychology began as a new domain of psychology in 1998 when Martin Seligman chose it as the theme for his term as president of the American Psychological Association. It is a reaction against past practices, which have tended to focus on mental illness and emphasized maladaptive behavior and negative thinking. It builds on the humanistic movement by Abraham Maslow, Rollo May, James Bugental and Carl Rogers, which encourages an emphasis on happiness, well-being, and positivity, thus creating the foundation for what is now known as positive psychology.Positive psychology focuses on eudaimonia, an Ancient Greek term for "the good life" and the concept for reflection on the factors that contribute the most to a well-lived and fulfilling life. Positive psychologists often use the terms subjective well-being and happiness interchangeably.Positive psychologists have suggested a number of factors may contribute to happiness and subjective well-being. For example, social ties with a spouse, family, friends, colleagues, and wider networks; membership in clubs or social organizations; physical exercise, and the practice of meditation. Spirituality can also be considered a factor that leads to increased individual happiness and well-being. Spiritual practice and religious commitment is a topic researchers have been studying as another possible source for increased well-being and an added part of positive psychology. Happiness may rise with increasing financial income, though it may plateau or even fall when no further gains are made or after a certain cut-off amount.