International study links cat density and parasites to national happiness

An international study published in the journal PLOS One has identified a complex relationship between feline presence, parasites, and national happiness levels across 93 countries. Led by researchers including Dario Maestripieri from the University of Chicago and Javier I. Borráz-León from Mexico’s National Institute of Psychiatry, the research analyzed data including GDP per capita, healthcare spending, and animal density.

The findings indicate a positive correlation between higher cat density per person and reported levels of national satisfaction. However, the study also identified a negative impact linked to the microorganism Toxoplasma gondii, a parasite commonly transmitted through feline feces. Countries with higher exposure to this parasite—measured via antibody seroprevalence in pregnant women—tended to report significantly lower levels of well-being.

Researchers noted that these two variables together explained up to 47% of the differences in happiness between the evaluated nations. The study emphasizes that economic prosperity and public health infrastructure play critical roles in balancing these factors, as wealthier nations often possess better resources to manage health risks associated with domestic pets.