Lane argues that the Easterlin paradox and the hedonic treadmill theory that happiness is ultimately unnecessary are actually not true. Lane points out that Easterlin's findings were mostly limited by data from Easterlin's time and that Lane's own investigations take a broader perspective on the relationship between money and happiness. Lane accepts Easterlin's identification that wealthier people are happier than poorer people. International surveys continue to reflect this trend, even twenty years after Easterlin's study. What Lane finds flawed in Easterlin's findings is that overall increases in wealth actually increase the overall body weight of a society. One thing Lane takes into consideration is that beyond a certain point, wealth can no longer buy happiness. It is only for the poor that happiness can be bought, because the poor do not have enough resources to ensure their survival, which makes finances a source of worry, and therefore an increase in negative affect. But among the rich, this worry disappears, because they have enough material resources to ensure their survival. Lane mentions that studies have found that "While the poor and less educated worry about their health, their income, and things they can't easily control, the wealthier and more educated worry more of their relationships with their spouses and children and more controllable aspects of their lives. Money doesn't reduce worry; it's simply