What makes people happy? Is happiness the result of internal personality traits or from external factors such as relationships, health, and job satisfaction?

Researchers explored this question in a study recently published in Nature Human Behaviour.

Their goal was to better understand the source(s) of happiness in order to develop better public policy approaches and programs to improve happiness at a societal level. “We have to understand the sources of happiness to build effective interventions,” said first author Dr. Emorie Beck, Assistant Professor of Psychology at the University of California, Davis.

If happiness is primarily attributed to external factors, then public policy approaches to improve happiness should target improving factors such as health and economic stability. However, if happiness is primarily driven by internal factors such as personal qualities and attitudes, policy approaches to improve happiness should focus on improving mental states through practices such as therapy, meditation, and/or mindfulness.

The scientists gathered survey data from over 40,000 people who had participated in prior surveys of life satisfaction over a period of up to 33 years. Respondents were from Great Britain, Switzerland, Germany, The Netherlands, and Australia, and the surveys assessed both global life satisfaction over time as well as satisfaction in five domains: relationships, work, health, income, and housing.

Their results showed that respondents fell into one of four roughly equal groups with respect to the primary drivers of their happiness: 1) internal personality traits (“top-down” model); 2) external factors (“bottom-up” model); 3) an interaction between internal and external factors; or 4) no clear connection with internal and external factors.

According to Beck, “What comes out is that we see roughly equal groups that demonstrate each pattern. Some are bottom up; some are top down, the domains don’t affect their happiness; some are bidirectional and some are unclear.”

In the group where no clear connection with internal and external factors was found, the researchers postulated that it is possible that there are other external factors driving their happiness that were not captured by the five domains that were studied.

These findings show that studies of happiness that average data across entire populations do not reflect individual variability. Public policy strategies for improving happiness across society that focus on only top-down or on only bottom-up approaches are unlikely to be successful. Instead, policies must provide the means for improving both internal and external factors while being flexible enough to be tailored to individuals.