An international team of researchers has discovered a link between the number of cats in a country and the level of happiness of its residents, a new study published in PLOS One shows. The study included publicly available data from 93 countries, and the analysis included the influence of the parasite Toxoplasma gondii, whose main hosts are cats.
Approximately one in three people worldwide are infected with the parasite Toxoplasma gondii. In most people, the infection is harmless and causes no symptoms, but in vulnerable groups it can lead to health problems. Previous studies have linked the infection to anxiety, depression and schizophrenia, which has further prompted scientists to examine the broader context.
The results of the analysis showed that countries with more cats generally recorded higher levels of happiness. On the other hand, countries with a higher rate of infection with the parasite T. gondii reported lower levels of happiness. Interestingly, countries with more cats had a lower, not higher, level of parasite exposure, suggesting a complex relationship between the number of cats, infection and happiness.
The researchers included the wealth of states in the analysis. In richer countries, people are more likely to have cats as pets and can afford better veterinary care for them. Cats in such conditions are more likely to live exclusively indoors, are regularly checked by vets and are fed commercial food, which reduces the spread of the parasite. This could explain why a higher number of cats does not necessarily correlate with a higher infection rate.
Scientists note that the overall results could be disproportionately influenced by individual countries, such as China, which has a high score on the happiness index despite a lower number of cats per capita. Researchers point out that these are correlations at the state level and that one cannot conclude that owning a cat directly makes people happier or that toxoplasmosis makes people unhier.
The study by biologist Javier I. Borráz-León of the National Institute of Psychiatry Ramón de la Fuente Muñiz in Mexico, one of the authors of the study, states that the results indicate that biological and ecological factors may play a role in the sense of happiness. The level of happiness in the population is important for public health, as people under stress and anxiety are less productive and more susceptible to illness. This study builds on previous findings about the positive effects of pets. Studies have shown that animals can help slow down cognitive decline. For more precise conclusions, future research should track cat owners and those who do not own cats at the individual level, rather than just at the state level, the scientists say.
