Nature and happiness in an individualist and a collectivist culture.

According to the attention restoration theory, exposure to nature (ETN) renews one's capacity to focus attention, which decreases cognitive fatigue and therefore may increase positive emotions. Indeed, natural settings have been associated with high prevalence of happy facial expressions (HFE). However, how universal the association is, remains unclear. We explored the ETN-HFE association in Boston, US, representing a less collectivistic culture, and Yokohama, Japan, representing a more collectivistic one. Evidence from satellite images and social network data, using geoinformatics and statistical tools, revealed that individuals from both societies exhibited more happiness when they were photographed in more natural settings. These associations varied with temporal variations expressed through weekly and annual effects. In addition, we found that the presence of others was also associated with prevalence of HFE in natural settings at Yokohama and Boston but the relation was significantly stronger in Boston. Despite some relatively minor differences between the countries, these results support the universality of the association between ETN and HFE.