Overview
- A paper published September 30, 2026 in PLOS One analyzed 93 countries and found that higher numbers of cats per capita were associated with higher national happiness scores.
- The same analysis showed that higher recent prevalence of the cat‑borne parasite Toxoplasma gondii tracked with lower national happiness, with recent infection levels predicting mood more strongly than long‑standing infection.
- When cat density, recent infection, long‑standing infection and national health spending were modeled together, cat density and recent Toxoplasma exposure were the strongest predictors and the four factors explained about 47 percent of country differences in happiness.
- The study found a counterintuitive pattern: countries with more cats tended to have lower recent Toxoplasma exposure, a result the authors say may reflect wealth differences such as indoor cat keeping, commercial feeding and routine veterinary care that reduce human infection risk.
- Authors and reporters stress major limits: the analysis is ecological and cross‑sectional, parasite data came from studies of pregnant women dated 1976–2017 while happiness and cat counts use 2022–25 figures, and the results cannot prove that cats cause happiness or that infection lowers mood, so individual‑level and longitudinal research is needed and the full dataset is available on OSF.