What can one do to permanently increase one's baseline happiness (subjective well-being)? According to the hedonic treadmill theory of subjective well-being each human has a hedonic set point. Positive or negative life events cause relatively short-term deviations to one's happiness before it returns to the baseline happiness level determined by the set point. The set point appears to be stable over the course of one's life. One's happiness, measured over time, looks something like this:



Question: What, if anything, has been demonstrated by research to cause long-term, significant upward shifts of the baseline happiness? And, if so, which of those interventions are accessible to an average person (in wealthy countries)?
Going off the findings in this paper, it seems that one's baseline level of happiness can be increased and maintained at a (weakly) significant level by &quot;continual effort and engagement in  some  intentional  process&quot; (Sheldon &amp; Lyubomirsky, 2006, pg. 59), which the authors refer to as &quot;activity-based changes&quot;. Examples given include, starting to exercise, beginning a new project, or gaining a new perspective.
This as opposed to circumstance-based changes which deliver only minimal, short-lived increases in happiness, such as getting a raise, or buying a new car.
I feel it is important to note that this is only one paper which uses a short time frame of only 6 months to measures changes in happiness. However, it seems then that to achieve lasting increases in our happiness set point, we are better off working on ourselves than our surroundings.