The Hedonic Treadmill: Why Getting What You Want Does Not Make You Happy

In 1978, Philip Brickman and colleagues published a study that should have been more famous than it became. They compared the happiness levels of lottery winners and people who had recently become paralysed through accidents. The lottery winners were expected to be much happier. The accident victims were expected to be much less happy. Neither expectation held up in the way anticipated.

The lottery winners were not dramatically happier than the control group. The accident victims were not dramatically less happy. Both groups had largely returned toward their baseline level of happiness within the timeframe of the study. Brickman called this the hedonic treadmill: life events move us up or down, but we adapt and return to our set point.

Subsequent research has confirmed and complicated this picture. The adaptation is not universal or complete. Serious conditions that involve ongoing discomfort, pain, and restriction of activity — like chronic pain or severe disability — may not fully adapt. Unemployment, to take another example, adapts more slowly than income gains. Noise and commuting also show limited adaptation.

But the general pattern holds: we are remarkably good at returning to our baseline. The pleasure from the new car fades within months as the new car becomes the current car. The delight of the promotion evaporates as the new salary becomes normal and new expectations establish themselves. The relationship that felt exhilarating becomes comfortable and then sometimes effortful.

This has practical implications for the gap between predicted and actual happiness. Dan Gilbert calls this the impact bias: we consistently overestimate how much positive events will improve our happiness and how much negative events will decrease it. The emotional immune system is more effective than we give it credit for, and the hedonic treadmill runs faster than we expect.

Sonja Lyubomirsky's research suggests that about fifty percent of baseline happiness is heritable, ten percent is attributable to life circumstances (income, marital status, health), and forty percent is influenced by intentional activity — how you spend your time and attention. The forty percent is where the research on happiness interventions operates. Practices like savouring, gratitude, variety, and investing in relationships tend to resist adaptation better than acquisitions and achievements.