People Typically Experience Extended Periods of Relative Happiness or Unhappiness due to Positive Feedback Loops Between LS and Variables Which are Both Causes and Consequences of LS

Long term panel data enable researchers to construct trajectories of LS for individuals over time. Bar charts of trajectories, and subsequent statistical analysis, show that respondents typically spend multiple consecutive years above and below their own long-term mean level of LS. We attempt to explain these multi-year waves of change by estimating structural equation models with two-way causal links between LS and variables usually treated as causes of LS, including health, frequency of physical exercise and frequency of social activities. Results are interpreted as showing positive feedback loops between these variables and LS, such that gains and losses of LS tend to be reinforced over time.