 To go along with this, four of the Big Five Personality Traits are substantially associated with life satisfaction, openness to experience is not associated.Having high levels of internal locus of control lead to higher reported levels of happiness.Even when happiness can be affected by external sources, it has high hedonic adaptation, some specific events such as an increase in income, disability, unemployment, and loss (bereavement) only have short-term (about a year) effects on a person's overall happiness and after a while happiness may return to levels similar to unaffected peers.