It is worth reading the Journal article by Sonja Lyubomirsky called Pursuing Happiness: The Architecture of Sustainable Change. In her article she talks about different factors affecting happiness, some that are in people’s control (“Intentional Activity”), some that are related to genetics (“Set Point”) and some that are related to “Life Circumstances”, such as demographics and the effect of certain personal life events. She suggests that we can make a difference to our level of happiness by focusing on “intentional activity” aspects, however she also points out that this requires effort. She divides this “intentional activity” into three types of effort: behavioural (such as exercising or being kind to others), cognitive (such as reframing situations or being grateful) and volitional (such as striving for important personal goals) and provides evidence from a range of research on how each one of the three factors has a positive affect on happiness. However, Sonja Lyubomirsky also argues that the effort becomes a lot easier, and more sustainable and enjoyable, if a person can find meaning and value in the activity.
Sonja Lyubomirsky also highlights how “happy people gain tangible benefits” including “superior work outcomes (greater creativity, increased productivity, higher quality of work, and higher income; e.g., Estrada, Isen, & Young, 1994; Staw, Sutton, & Pelled, 1995), and more activity, energy, and flow (e.g., Csikszentmihalyi & Wong, 1991)”.
Shawn Achor builds on these findings in his entertaining TED talk on “The happy secret to better work”