Moderately happy people are wealthier - and maybe healthier - than extremely happy individuals, says a psychologist who has researched happiness for more than two decades.
While people who are happy are certainly more healthy and successful than those who are angry and depressed, Dr Ed Diener ofthe University of Illinois said people who are moderately happy may achieve more than those who are extremely happy. They might also live longer.
"Our findings suggest that extremely high levels of happiness might not be a desirable goal and that there is more to psychological wellbeing than high levels of happiness."
Diener and his team looked at six different studies of happiness and life outcomes to investigate the optimum level of happiness.
One study, the World Values Survey, which included nearly 120,000 people from 96 countries, found that those who were moderately happy, rating their life satisfaction at 8 or 9 out of 10, made more money than those who rated their satisfaction level at 10. However, 10s and 9s were more likely to have stable intimate relationships.
In four studies that looked at individuals' wellbeing several years after their happiness level was initially assessed, the happiest people wound up with less education and lower incomes than moderately happy individuals.
While the current study didn't look at happiness and health, Diener said other research has shown that the happiest people may not live as long as moderately happy individuals.
Extremely happy people may be less likely to follow up on health concerns, he suggested. It's also possible, he said, that being in an "aroused", extremely happy state can take a toll on one's cardiovascular system. People for whom extreme happiness is a goal may also be thrill-seeking risk takers.
As far as achievement goes, Diener said, extremely happy people may be more satisfied with their lot in life.
"Maybe we're not built to be ecstatic all the time; maybe we need some negative emotions," said Diener. But this isn't to say, he added, that it's a good thing to be unhappy.
"If you're a 4 you probably ought to get help," he suggests. "If you're an 8 ... maybe that's good enough, you don't need to take Prozac."
