What is the hedonic treadmill?

The short answer

The hedonic treadmill, or hedonic adaptation, is the tendency to return to a fairly stable level of happiness after good or bad changes in life. The new car, the raise, the bigger apartment: each gives a lift that fades as it becomes the new normal. The term was coined by psychologists Philip Brickman and Donald Campbell in 1971. You can keep running. The treadmill keeps moving.

The lottery study

In a famous 1978 study, Brickman and colleagues found that lottery winners were not much happier than comparison groups a while after winning, and took less pleasure in everyday things. It's a small, old study and not the last word, but it became the go-to evidence that the jackpot doesn't buy a permanent upgrade. Later research found that adaptation isn't always complete; some major events, like long-term unemployment or disability, can shift well-being for years.

So can money buy happiness?

A bit, and it's complicated. A 2010 study by Daniel Kahneman and Angus Deaton found day-to-day emotional well-being rose with income but leveled off around $75,000 a year. Later work by Matthew Killingsworth found it kept rising. In 2023 the researchers teamed up and found both were partly right: for most people, happiness keeps climbing with income, but for the least happy fifth it plateaus around $100,000. In other words, money helps, just not with everything, which is roughly what the paywall was hoping you wouldn't notice.

What seems to slow the treadmill

Research points to things that adapt more slowly than possessions: relationships, experiences over stuff, gratitude, variety, and time spent on things that feel meaningful. None of them comes with a premium tier. If low mood won't lift, that's worth raising with a doctor or therapist rather than a checkout page; in a crisis in the U.S., call or text 988.