“One interesting new theory, developed by Edward and Carol Diener at the University of Illinois in Urbana, involves the notion of a 'set point'. According to this theory, people have an inborn set point for mood, similar to the set point for weight. The set point is your basic level of happiness or sadness, which is subject to ups and downs of life but will inevitably return to some kind of base line, even in people who experience dramatic changes in their life circumstances. [...] In some people, however, set points decline with age.” A Users Guide To The BrainJohn J RateyUniversity Of IllinoisCarol DienerEdward DienerEmotional Set Point Book:A User's Guide to the Brain: Perception, Attention, and the Four Theaters of the Brain Source: A User's Guide to the Brain: Perception, Attention, and the Four Theaters of the Brain