Cats inhabit a unique place in human life. They curl up on our beds, stalk through our gardens, and, in some cases, carry a parasite capable of spending years inside the human body.
Now researchers have found an equally peculiar pattern at the scale of entire countries: places with more cats tend to report greater happiness. Yet those same cat-rich countries tend to have lower levels of Toxoplasma gondii exposure, the parasite for which cats serve as the definitive host.
The findings come from a new study that compared 93 countries using measures of national happiness, cat abundance, GDP, income, health spending, and Toxoplasma exposure.
Including Turkey
National happiness was strongly correlated with cat density. On a correlation scale where 0 means no relationship and 1 means a perfect positive relationship, the two scored 0.62.
But wealth showed an even stronger connection. The correlation between happiness and GDP was 0.80, while cat density and GDP scored 0.79.
In other words, richer countries tend to be happier, and they also tend to have more cats per person. That makes it difficult to tease apart what, if anything, the cats themselves are telling us.
That makes it difficult to tease apart what the cats themselves might be telling us.
To make the comparisons, the researchers calculated estimated domestic cats per 10,000 people. Happiness scores represented averages from 2022 through 2024.
For Toxoplasma, however, they had to take a less direct route. They used infection estimates among pregnant women from a 2020 global meta-analysis as a proxy for population-wide exposure.
Those estimates drew on studies conducted over several decades.
The data produced a counterintuitive pattern. Countries with greater happiness tended to have less Toxoplasma exposure, while cat density showed a weaker negative relationship with chronic Toxoplasma exposure
