Hedonic Treadmill

A hedonic treadmill (also called hedonistic treadmill and hedonic adaptation) is the tendency of a person to remain at a relatively stable level of happiness despite a change in fortune or the achievement of major goals. According to the hedonic treadmill model, as a person makes more money, expectations and desires rise in tandem, which results in no permanent gain in happiness.

The hedonic treadmill theory explains the often-held observation that rich people are no happier than poor people, and that those with severe money problems are sometimes quite happy. The theory supports the argument that money does not buy happiness and that the pursuit of money as a way to reach this goal is futile. Good and bad fortunes may temporarily affect how happy a person is, but most people will end up back at their normal level of happiness.

In psychology, a hedonic set point is the general baseline level of happiness a person experiences over their lifetimes, despite any temporary changes in the level from positive or negative life events. The theory argues that although events and environmental factors can affect happiness in the short term, people will naturally adapt back to their hedonic set point in the long term.

An interview-based study titled "Lottery Winners and Accident Victims: Is Happiness Relative?" that was published in 1978 by Brickman, Coates, and Janoff-Bulman set out to determine how people adapted to happiness. The researchers interviewed three groups of people: lottery winners, paralyzed accident victims, and a control group.

Based on their findings, the newly-rich lottery winners were shown to have similar levels of happiness before and after winning. This indicated that there wasn't a consistent relationship between increased happiness and personal financial gains, and that the baseline level of happiness for the lottery winners over time would remain nearly the same.

According to the study, "Although lottery winners felt very good about winning the lottery, they took less pleasure than controls [group] in a variety of ordinary events and were not in general happier than [the control group]. These results can be derived from an adaptation level analysis of the effects of a single extremely positive event."

The study also showed that the group of paralyzed accident victims expected their level of happiness to increase to the baseline over time, despite an initial decrease in happiness from their negative life event.