Global Study Links Cat Density to National Happiness
An analysis of 93 countries finds nations with more cats per capita report higher happiness and lower rates of the Toxoplasma gondii parasite.
Countries with more cats per capita tend to have higher levels of national happiness. A new global study of 93 nations also found these countries often have lower rates of infection from the parasite Toxoplasma gondii, which is spread by cats. The research, published Wednesday in PLOS One, reveals a strong association between cat density and reported well-being at a national level.
Wealthier countries exhibit higher happiness rates, lower levels of T. Gondii infection, and have more cats. The study's lead author, Javier I. Borráz-León of the Secretariat of Science, Humanities, Technology, and Innovation in Mexico City, suggests this is due to more indoor cat keeping, commercial feeding, and veterinary care in affluent nations. These practices likely reduce environmental contamination with the parasite. The analysis used infection data from pregnant women as a proxy for community-level exposure due to a scarcity of comprehensive national data.
Wealth and Care Reduce Parasite Spread
Researchers gathered national data from 93 countries including the UK, US, Australia, Canada, China, and Russia. They found countries with more cats per 10,000 inhabitants tended to have higher levels of reported happiness. Conversely, more people infected by the parasite in a country correlated with lower national happiness. The team's base hypothesis was that nations with higher socioeconomic indicators would exhibit higher happiness levels. The data supported this, showing wealth, cat numbers, and lower parasite prevalence are interconnected.
Lead Researcher Emphasizes Nuance and Responsibility
Javier I. Borráz-León, a researcher at the Behavioral Biology Lab of the National Institute of Psychiatry Ramón de la Fuente Muñiz and a self-identified cat lover, stresses the findings are correlational. The study cannot determine if getting a cat would make an individual happier. Borráz-León stated he would not interpret the findings as a reason to fear cats. Instead, he emphasized the importance of responsible pet ownership.
"I would not interpret our findings as a reason to be afraid of cats," Borráz-León said. "Instead, they highlight the importance of responsible pet ownership." He noted the analysis shows positive associations between cat density, some socioeconomic factors, and national happiness, alongside negative associations with T. Gondii infection rates. The association was strong and remained after controlling for other variables. Finland, the happiest country analyzed, had an above-average number of cats per capita, as did the United States.
How Toxoplasma Gondii Affects Humans
Toxoplasma gondii is a single-celled parasite that can only reproduce in the feline digestive system. Most people infected are asymptomatic, with symptoms like fever and aches sometimes mistaken for flu. However, people with weakened immune systems may develop serious complications including inflammation of the brain and lungs. In pregnant women, early infection carries a heightened risk of miscarriage, stillbirth, or neurological damage.
Humans catch the parasite primarily by swallowing its eggs in cat feces, not by petting cats. Of infected cats, only a minority shed eggs, and only for two to three weeks. Infection can also come from eating rare meat from infected herbivores or fresh produce grown in contaminated soil. Some unproven studies suggest transmission during sex. About 10 to 30 percent of the global population is infected without knowing it. Separate research has linked the parasite to road rage, depression, and other mood changes in humans.
The study's authors call for further research into whether biological and ecological factors like cat density can reveal well-being patterns beyond economic measures. The research idea was to explore if such factors could reveal patterns not captured by conventional economic measures. Dog or hamster density as a variable underlying national happiness has not been examined. The full study, 'Wealth, health, cats and Toxoplasma gondii,' is available in PLOS One with the DOI 10.1371/journal.pone.0357911.
