Article summary of Beyond the hedonic treadmill: Revising the adaptation theory of well-being by Diener et al. - Chapter

What is this article about?

The hedonic treadmill model is a model that supposes that good and bad events can only temporarily affect happiness. According to this model, everyone always adapts back to hedonic neutrality. This leads to the conclusion that it is pointless to try and increase happiness. The poorest diseased beggar with no social connections could be just as happy as the healthy billionaire with a lot of close and supportive relationships. But is this really true? This article will make five important revisions to the hedonic treadmill model:

1. Individuals' set points are not hedonically neutral.
2. People have different set points, partly depending on their temperaments.
3. A single person may have multiple happiness set points.
4. Well-being set points can change under some conditions.
5. Individuals differ in their adaptation to events.

What is the hedonic treadmill theory?

In 1971, Brickman and Campbell came up with the hedonic treadmill. According to them, processes similar to sensory adaptation occur when people experience emotional reactions to life events. Just like we get used to sensory input and are quickly not aware anymore of smells or sounds, we adapt to emotions as well. Myers added to this theory that every desirable experience is transitory. According to the original treadmill theory of Brickman and Campbell, people briefly react to good and bad events, but in a short time they return to neutrality. The theory is based on the automatic habituation model in which psychological systems react to deviations from one's current adaptation level. Automatic habituation processes are adaptive because they allow constant stimuli to fade into the background.

In 1978, Brickman, Coates, and Janoff-Bulman offered initial empirical support for the treadmill model. Brickman had for example studied lottery winners and found that they were not happier than nonwinners. It was also found that people with paraplegia, an impairment in the motor and sensory function of the lower body, were not less happy than people who could walk. The idea of hedonic adaptation was appealing in psychology because it offered an explanation for the observation that people appear to be relatively stable in happiness despite changes in fortune. The theory was widely accepted in psychology. Evidence frequently supported the idea. There soon came longitudinal studies that tracked changes in happiness over time. These studies provided more direct evidence that adaptation can occur. For instance, Silver found that people with spinal cord injuries had strong negative emotions after their crippling accident, but that these negative emotions had already faded after two months. 

What revisions can be made to the original hedonic treadmill model?

Are set points always neutral? 

The first revision that can be made, is that set points might not always be neutral. The original treadmill theory suggested that people return to a neutral set point after an emotionally significant event. Research now shows that this part of the theory is wrong. Most people are not neutral most of the time, but happy. So, if people adapt and return to a baseline, this baseline is a positive one and not a neutral one. 

This tendency to experience positive emotions may provide the motivation to explore one's environment and to approach new goals, so also to adapt to unpleasant experiences. 

Are set points the same across individuals?

The research since Brickman and Campbell's reveals that if people do have set points, they vary considerably across individuals. These individual differences are for a certain part due to inborn, personality-based influences. Research consistently shows that one's level of well-being is reasonably stable over time, moderately heritable and has strong correlation with personality factors. Thus, personality factors may predispose people to experience different levels of well-being. 

Does someone have only one happiness set point?

The idea of a happiness set point implies that well-being is a single entity with a single baseline. But research by Lucas, Diener and Suh in 1996 indicates that a global category of happiness is composed of separable well-being variables. There is no single set point but there are various components that exhibit differential stability. Research specifically show that stable individual baselines are more characteristic of negative affect than of positive effect. Research does show that over a longer period of a few years, life satisfaction, so positive affect, is also stable. 

Can happiness change?

This is perhaps the most drastic revision. The most controversial aspect of Brickman and Campbell's hedonic treadmill model is the idea that people cannot do much to change their long-term levels of well-being. Adaption would be inevitable and changes in life circumstances could never lead to lasting changes in happiness. Until recently, there have not been good longitudinal tests of this hypothesis. Questions have remained about the extent to which important life events can permanently alter individuals' happiness set points. 

Evidence for the hypothesis that life circumstance matter for well-being comes from the fact that well-being differs across nations. There are strong national differences in well-being that can be predicted from objective characteristics of the nations. This suggests that the stable external circumstances that vary across nations have a lasting impact on happiness. Happiness can and does change long-term.

It should be noted that the classic empirical findings of Brickman et al. were not as strong as evidence as many psychologists have assumed. The study of people with spinal cord injuries was done again and the researchers found that the difference between the spinal cord-injured people and control groups was about 0,75 standard deviations. Most psychologists would consider this a large effect. Individuals with spinal cord injuries are in fact less happy than are people in the general population.

It is a fact that there are people that live in negative circumstance and still report well-being scores that are above neutral. This is an interesting and important fact, but it should not be used as evidence that people inevitably adapt. To determine whether adaptation has occurred, it is necessary to compare individuals who have experienced an event or life circumstance with those who have not, ideally following the same individuals over time. 

Are there individual differences in adaptation?

The final revision that can be made is that of the implicit assumption of the hedonic treadmill theory that adaptation to circumstances occurs in similar ways for all individuals. Researchers have found individual differences in the rate and extent of adaptation that occurs even to the same event. For example, people with initially low baselines are more likely to benefit from marriage in the long run, as they reported more positive reactions to marriage and these positive reactions persisted long into the marriage.

By relying on very large samples, researchers in recent studies have been able to track individuals from before an event happens to the time of the event to many years after. Large longitudinal designs also allow for more precise measurement of changes in happiness over time and more powerful statistical methods that go beyond examinations of group means to reveal individual differences in adaptation. The representative samples of participants have also grown larger. This has led to much stronger tests of the hedonic treadmill theory. 

What are the implications of the revised model?

Even though these revisions had to made to the original hedonic treadmill model, adaptation is still an important concept for psychological research. Recent studies have challenged the idea that adaptation is inevitable. We can now conclude that people do adapt to many life events, but there is a limit on the types of psychological processes that can account for the adaptation that does occur. The hedonic treadmill model should always be seen in the light of these revisions.

This is particularly important for the idea that we can do something about people's happiness. Interventions can cause lasting changes among individuals. This makes it possible to change the happiness of individuals and of a society as a whole. But we should also not be too optimistic in this possibility for change, because processes of adaptation must still be carefully considered. Factors that lead to lasting change need to be further researched.