Despite the apparent luster of achieving a predominantly positive state of mind, critics argue that the pursuit of happiness is a misguided goal- it's fleeting, superficial, and hedonistic. Research backs up some of these claims. Studies conducted in 2013 by psychologist Ed Diener show that people actually pay an emotional price for intensely positive events because later ones- even moderately pleasant ones- seem less shiny by contrast. Perhaps more damning is a series of studies led by University of California, Berkeley, psychologist Iris Mauss, which revealed that people who place a premium on being happy report feeling more lonely. In a 2013 study, researchers at University of California, Los Angeles (UCLA), and University of North Carolina at Chapel Hill reported that happiness levels have powerful effects on genes and our health. But there was a catch: the specific kind of happiness mattered a lot. The unselfish happiness, whose feelings of well-being involved a deep sense of purpose in life, had a strong expression of antiviral and antibody genes. Happy hedonists, meanwhile, wrapped up in materialistic pleasures, had weaker immune systems. 'Even pleasures that seem virtuous, like looking at a sunset, can be hedonic, because they involve one's own emotional gratification,' explains UCLA professor Steven Cole.