A Genetic Component to National Differences in Happiness

National differences in subjective well-being (SWB) have been attributed to socioeconomic, climatic, and genetic factors. We focus on one particular facet of SWB—happiness or positive affect—measured by the nationally representative World Values Survey (WVS). We find that national percentages of very happy people across the three latest WVS waves (2000–2004, 2005–2009, 2010–2014) are consistently and highly correlated with national prevalence of the rs324420 A allele in the FAAH gene, involved in the hydrolysis of anandamide, a substance that reportedly enhances sensory pleasure and helps reduce pain. Climatic differences are also significantly associated with national differences in happiness, whereas economic wealth, recent economic growth, rule of law, pathogen prevalence, and the distribution of short versus long alleles in the serotonin transporter gene SLC6A4 are not significant predictors of national happiness.