Hedonic Treadmill (Adaptation)
Hedonic Treadmill (also referred to as Hedonic Adaptation) refers to the notion that after positive (or negative) events, and a subsequent increase in positive (or negative) feelings, people return to a relatively stable, baseline level of affect.
It is a process or mechanism that reduces the affective impact of emotional events. The process is often conceptualized as a treadmill, since no matter how hard one tries to gain an increase in happiness, one will remain in the same place.
Hedonic adaptation can occur in a variety of ways. Generally, the process involves cognitive changes, such as shifting values, goals, attention and interpretation of a situation. The process of adaptation can also occur through the tendency of humans to construct elaborate rationales for considering themselves deprived through a process called -- abundance denial.
For example, a person moving into a 400-square-foot apartment may not initially observe much of a difference between her apartment and the 450-square-foot apartment next door. However, after she adapts to her current apartment, the apartment next door begins to appear much larger and more favorable in comparison. She may even become motivated to try to switch apartments.
It is different from
desensitization. Desensitization is characterized by reduced sensitivity toward differences in a stimulus. People who are desensitized would not notice the difference between their current 400-square-foot apartment and the 450-square-foot apartment next door, nor would they be motivated to attempt to substitute their apartment for the larger one. Thus, although desensitization and hedonic adaptation share certain characteristics, hedonic adaptation cannot be explained as merely desensitization to a stimulus.
Hedonic adaptation may be a more common phenomenon when dealing with positive events as opposed to negative ones. Negativity bias, where people tend to focus more on negative emotions than positive emotions, can be an obstacle in raising one's happiness set point. Negative emotions often require more attention and are generally remembered better, overshadowing any positive experiences that may even outnumber negative experiences. Given that negative events hold more psychological power than positive ones, it may be difficult to create lasting positive change.
Source: The Effects of Variety and Novelty on Physical Activity and Healthy Nutritional Behaviors