Brickman and Campbell (1971, in Diener, 2000) suggested that all people labor on a “hedonic treadmill. ” As they rise in their accomplishments and possessions, their expectations also rise. Soon they habituate to the new level, and it no longer makes them happy. On the negative side people are unhappy when they first encounter misfortune, but they soon adapt and it no longer makes them unhappy. On the basis of this reasoning, Brickman and Campbell proposed that people are destined to hedonic neutrality in the long run.
This, points toward the theory of adaptation (Diener, 1984) that people adapt to most conditions very quickly. For example, Suh, Diener, and Fujita (1996) found that in less than three months the effects of many major life events (e. g. , being fired or promoted) lost their impact on SWB. People do react strongly to good and bad events, but they then tend to adapt over time and return to their original level of happiness (Brickman & Campbell, 1971).
The theory of ‘hedonic treadmill” of Brickman and Campbell has been refined in several ways. First, people may not adapt back to neutrality but may instead return to a positive set point. Diener and Diener (1995) noted that most of SWB reports are in the positive range, above the neutral points of the scales. The set point first postulated by Brickman and Campbell actually might be in the positive range because humans are predisposed to feel predominantly pleasant affect if nothing bad is happening (Diener, 2000).
Another refinement of the hedonic treadmill idea is that the baseline level of happiness to which people return is influenced by their temperament. One reason to integrate personality with the concept of adaptation is that personality predispositions appear to be one of the strongest factors influencing long-term levels of SWB. To underscore this point of argument, Diener (2000) quotes Goldsmith (1996): The partial heritability of happiness is supported by research on early temperament that suggests that emotional reactivity emerges early in life and is moderately stable over time.
Diener and Larsen (1984, in Diener, 2000) found that participants’ average moods showed a substantial amount of consistency across both situations and time, suggesting that SWB is not a result only of situational factors. Although peoples mood fluctuate from moment to moment, there is a strong degree of stability in mean levels of mood experienced, even a period of years and across varying life circumstances.
Advantageous and disadvantageous events move individuals temporarily away from their personal baseline, but over time they return to them. In support of the idea of adaptation, research evidences report (Diener, 2000) that long-term marriage and widowhood did not influence levels positive and negative affect. Scientists are exploring why people adapt to conditions. Although reasons for adaptations are not fully understood, it is clear that people do not habituate completely to all conditions.
It is also found that people adapt rapidly to some circumstances (e. g. , imprisonment) and adapt little or not at all to other conditions (e. g. , noise, sex). Although personality is undoubtedly an important contributor to long-term levels of well-being, it is an exaggeration to conclude that circumstances have no influence. People’s set points appear to move up or down, depending on the favorability of long-term circumstances in their lives (Diener, 2002).