Hedonic Treadmill

011 min

The hedonic treadmill at a glance

• What it is: After an event, happiness moves for a while and then drifts back toward where it was before.
• Origin: Brickman and Campbell named it in 1971, and Brickman, Coates and Janoff-Bulman tested it on lottery winners in 1978.
• Watch for: The drift back is often incomplete, so "people adapt to everything" is wrong.
• Guard against it: Before a big purchase or career move, estimate how much the gain will last from people who already made the change, not from how you feel now.

021 min

Where the hedonic treadmill shows up

Here is an illustrative scenario. A staff engineer negotiates a raise from $180,000 to $210,000 a year. In the first month they check each payslip and feel the difference. By month twelve they no longer notice the extra income. They now compare their pay with the new figure, and with what colleagues at the next level earn. The raise is still real, but it no longer feels like a gain.

Now change one input. The same engineer gets the same raise, but a peer on the team is raised to $240,000 in the same week. The first month feels smaller, and the comparison starts at a higher figure. The amount received is identical. The feeling differs because the reference point differs.

The pattern in both cases is the same. A change makes a difference to how a person feels, the difference shrinks as the change becomes ordinary, and the person then judges the next change against the new level. The same sequence appears with a new phone, a bigger office, a promotion, and a feature that users loved in its first week. It also appears after a bad event.

032 min

Why the hedonic treadmill happens

The theory rests on adaptation-level theory, which holds that people judge a stimulus by comparing it with what they have recently experienced, not by its absolute size. Brickman and his co-authors described two processes that follow from it. The first is contrast: a peak experience makes ordinary pleasures feel smaller by comparison. The second is habituation, which means getting used to something so that it produces less response each time.

In their 1978 paper they predicted that contrast with the peak experience of winning should lessen the impact of ordinary pleasures, while habituation should eventually reduce the value of new pleasures made possible by winning. Both processes push happiness back toward its earlier level.

A third process is that aspirations rise with circumstances. Lindqvist, Östling and Cesarini describe the hedonic adaptation literature as arguing that people adjust their aspirations upwards when their economic conditions improve. A higher standard turns a gain into the new minimum. This comparison resembles anchoring, where an earlier number sets the reference for later judgments, except that here the reference is a person's own recent experience.

Adaptation is not the same as diminishing returns. Diminishing returns says each extra unit adds less than the one before. Adaptation says the reference level itself moves, so even a unit of the same size feels smaller on the second day than on the first.

There is also an adaptive reason. Gilbert and colleagues describe a "psychological immune system", a set of mental processes that reduce the pain of bad events. People are generally unaware of it, which is why they overestimate how long a bad event will hurt. Without it, one bad week could decide a person's mood for years.

This article does not claim a brain mechanism, such as a reward chemical running out, because the evidence reviewed here is about reported well-being, not brain activity.

041 min

Where the hedonic treadmill comes from

Philip Brickman and Donald T. Campbell introduced the term in a 1971 chapter titled "Hedonic Relativism and Planning the Good Society", published in a book on adaptation-level theory edited by M. H. Appley. Their concern was social policy: if people judge their lives against a moving reference level, improving conditions for everyone may not make everyone happier.

The empirical test came seven years later. Brickman, Coates and Janoff-Bulman (1978) compared 22 major lottery winners with 22 controls and with 29 paralyzed accident victims who had been interviewed previously. They asked each group how happy they were now and how much pleasure they took in a series of mundane events.

The original study is small, with groups of 22, 22 and 29 people. It was a starting point, not a final word, and later work, described below, both extends and contests it.

051 min

An example: lottery winners and accident victims

The 1978 result is the most quoted case. Brickman, Coates and Janoff-Bulman found that lottery winners were not happier than controls and took significantly less pleasure from a series of mundane events. The authors read the second finding as contrast: after the peak of winning a fortune, ordinary events felt smaller.

Their second study checked two alternative explanations. It indicated that the effects were not due to preexisting differences between people who buy or do not buy lottery tickets, or between interviews that made or did not make the lottery salient. In other words, they tried to rule out that lottery players were already different, and that being asked about the lottery changed the answers.

The accident victims added a twist. Paraplegics also demonstrated a contrast effect, not by enhancing minor pleasures but by idealizing their past, which did not help their present happiness. This is a contrast too: the comparison point was their own earlier life.

A later economics paper re-read the same study. Lindqvist, Östling and Cesarini describe it as a famous comparison of the happiness of 22 major lottery winners of the Illinois State Lottery to that of 22 controls domiciled in the same regions as the winners. They note it found no statistically significant differences in happiness between winners and controls, and that its prizes were very large compared with those in later studies.

062 min

A second case: marriage, unemployment, and disability

The 1978 study looked at one lottery. Panel studies, which follow the same people for many years, give a different picture because they measure each person before and after an event. Two of the studies below use the same German survey, which followed over 24,000 individuals for 15 years.

The variable that differs from the lottery case is the type of event. A prize changes finances, and the 1978 study found no lasting gain in happiness. Unemployment and disability change daily life in ways that can stay in place, and the data show less return. The studies do not prove that this difference in the event is the cause, so treat it as a reading.

Two details stand out. In the unemployment study, people who had been unemployed before did not react any less negatively to a new bout of unemployment than people who had not been unemployed. If people simply got used to bad events, a second one should hurt less. And in the marriage study, the authors say individuals who initially reacted strongly were still far from baseline years later, and many people showed paths in the opposite direction from what adaptation theory predicts.

What the contrast teaches is that adaptation depends on the kind of event and on the person. The lottery case shows that a gain can fade into the background. The disability and unemployment cases show that some losses do not.

072 min

Where the evidence on the hedonic treadmill is contested

The strongest challenge comes from within the same research tradition. Diener, Lucas and Scollon (2006) wrote a review titled "Beyond the hedonic treadmill: Revising the adaptation theory of well-being". They argued that five revisions to the treadmill model are needed: set points are not hedonically neutral, people have different set points, one person may have several set points for different parts of well-being, set points can change under some conditions, and people differ in how they adapt. A set point is the level of happiness a person returns to, on this view.

The fourth point is the one the authors call perhaps the most important. Diener, Lucas and Scollon (2006) argued that well-being set points can change under some conditions. That directly contradicts the claim that people always return to where they began.

The second challenge is about money. Lindqvist, Östling and Cesarini (2020) surveyed Swedish lottery players 5 to 22 years after the prize and used the random assignment of prize size to compare winners with matched players. They report that large-prize winners experience sustained increases in overall life satisfaction that persist for over a decade and show no evidence of dissipating with time. Their sample is 3,362 players and a prize pool of $277 million, far larger than the 22 winners in 1978.

The strongest version of the treadmill objection should be stated fairly. The Swedish authors do not claim that happiness is unaffected by adaptation. They write that their design is not suited to studying short-run adaptation, because they did not survey any players within five years of the lottery. They also find that the estimated effects on happiness and mental health are significantly smaller than on life satisfaction. So both camps can be partly right: life satisfaction, a person's overall evaluation of their life, may stay higher, while moment-to-moment mood moves less.

For a practitioner, this leaves one rule. Treat the treadmill as a strong pull on short-run feelings, not as a guarantee that nothing you do will matter.

081 min

How the hedonic treadmill idea changed since 1971

The meaning has shifted since Brickman and Campbell. Their 1971 argument and the 1978 lottery study were read as saying that people return to a neutral level whatever happens. That reading spread widely, and the abstract of the 2006 review says the theory "has gained widespread acceptance in recent years" and implies that efforts to increase happiness are doomed to failure.

Between 2003 and 2007, Lucas and colleagues used long panel surveys to test that idea on marriage, unemployment, and disability. In 2006, Diener, Lucas and Scollon turned that evidence into five revisions. In 2020, Lindqvist, Östling and Cesarini added a large lottery sample with random prizes. Current practice no longer matches the original meaning. The idea that survives is narrower: people do adapt, often strongly, but the amount depends on the event, the person, and the type of well-being measured.

092 min

How the hedonic treadmill shows up in product, design, and AI

For a builder. A product team often sees user delight peak in the first days after a launch and settle afterward. That pattern can come from adaptation, but it can also come from a novelty effect, from a change in who uses the product, or from a measurement artifact. Do not assume the cause. A controlled experiment, such as an A/B test run long enough to pass the first week, separates a lasting change from a temporary one, because it compares users with and without the change over the same period.

For a designer. Users judge a redesign against the interface they just left, not against a neutral standard. A faster page that users had no complaints about gets little credit. A slower one gets blamed more than its absolute speed deserves.

For an analyst or an evaluator of AI. The same reference-point problem appears when people rate AI outputs over time. Early users may rate a chatbot's answers as impressive, and later users, with higher expectations, may rate the same answers lower. If raters are not the same people in each period, a drop in scores may reflect changed expectations, not changed quality. This is an illustrative pattern, not a result from a particular study, so check it with fixed benchmark prompts.

Exploited or accidental. Most of these cases are accidental. The deliberate case is a plan that relies on a new item feeling ordinary after a while, so that a buyer wants the next one.

102 min

How to guard against the hedonic treadmill

Knowing about the pattern is not enough. Gilbert and colleagues found that people are generally unaware of the mental processes that soften bad events, and so they overestimate how long a bad event will hurt. A forecast made from the current feeling will be off, whatever you know about adaptation. Use a method that changes the forecast instead.

1. 1

   Ask people who already made the change.

   This is a form of reference-class forecasting, which means predicting from the results of similar past cases, not from your own case. Before a role change, a move, or a purchase, ask three or four people who did it a year ago how they feel now. Their answer corrects the vivid picture in your head.

2. 2

   Set a review date.

   Write down, before the decision, how you expect to feel in twelve months and what you will check then. A dated prediction can be compared with what happened, which a vague hope cannot.

3. 3

   Separate the gain from the comparison.

   Name which part of a goal depends on comparison with others or with your own past. Those parts adapt fastest. Parts that change daily routines, such as shorter commute, less debt, or less pain, are the ones the long-run studies suggest last longer. That second claim is a reading of the research, not a proven rule.

4. 4

   Measure the long run in products.

   Track satisfaction for the same users at one week and at three months, not only at launch.

None of these methods guarantees lasting gains. They make the forecast closer to what usually happens.

111 min

Common misunderstandings

"Lottery winners are no happier than anyone else." This is the popular version of the 1978 study, and it overstates it. The original sample was 22 winners, and a later study with 3,362 Swedish players found sustained increases in overall life satisfaction. The popular claim holds, at most, for moment-to-moment happiness, and even there the evidence is mixed.

"Everyone returns to the same happiness level." The 2006 review says the opposite on both counts: set points are not hedonically neutral, and people have different set points, partly dependent on their temperaments.

"Adaptation always happens." Lucas (2007) found that long-term disability was associated with moderate to large drops in happiness, followed by little adaptation over time. Adaptation is common, not universal.

"The treadmill means there is no point trying to improve your life." The 2006 review states that its revisions offer hope for those who aim to decrease human misery and increase happiness. The treadmill is a reason to choose carefully, not a reason to stop.

Where adaptation is useful. For bad events, adapting is the healthy outcome. The process Gilbert and colleagues describe reduces the pain of negative events, and guarding against it would mean keeping a person in distress longer than necessary. The goal is accurate forecasts, not less adaptation.

122 min

The hedonic treadmill vs. nearby concepts

The nearest neighbor is hedonic adaptation. Hedonic adaptation is the process by which a person returns toward a baseline level of happiness after a change in life circumstances. The hedonic treadmill is the name for the full theory built on it, including the claim that the return is close to complete, so that pursuing gains does not raise lasting happiness. Most of the research cited here tests the strong claim and finds it too strong. The name compares the pattern to a treadmill, on which a person moves but stays in the same place.

The separating question is time. Loss aversion explains how a single judgment is made. The treadmill explains how feelings about the same circumstance change as months pass.

132 min

Frequently asked questions about the hedonic treadmill

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