It has become increasingly clear that COVID-19 transmits between individuals. It stands to reason that the spread of the virus depends on sociocultural ecologies that facilitate or inhibit social contact. In particular, the community-level tendency to engage with strangers and freely choose friends, called relational mobility (RM), entails increased opportunities to interact with a larger and more variable range of others. It may therefore be associated with a faster spread of infectious diseases, including COVID-19. Here, we tested this possibility by analyzing growth curves of confirmed cases and deaths of COVID-19 in the first 30 days of the outbreaks in 39 countries. We found the growth was significantly accelerated as a function of a country-wise measure of RM. This relationship was robust either with or without a set of control variables, including demographic variables, reporting bias, testing availability, and cultural dimensions of individualism and government efficiency. Policy implications are discussed.

Accepted for COVID-19 fast-track publication in Psychological Science