In his book The Pursuit of Happiness, psychologist David Myers reviewed research on the relationship between money and happiness. He found that once personal income had reached a stable but rather modest level, more income didn't make people any happier. Instead, what made people happy was more time with friends and family. He concluded that happiness often involves living a simple life, consuming less, and savoring more. He cited a study that found that the less expensive recreation is, the more people enjoy it. Americans actually rate themselves higher on happiness scales when they are gardening than when they are snow skiing or power boating.