Are we really a planet of zombie slaves being mind controlled by a cat-bourne brain parasite? According to some cat-hating contrarians, single-celled protozoa, Toxoplasma gondii, routinely take over our psyche, convincing us that our happiness lies in pampering our perfect pets.
That’s right gammas, chug down your Soma, zip up your cami knickers and forget about life’s worries as Lord Tybalt of Floofington gobbles down his dinner.
O brave new world that has such people in’t!
Anti-fans of our feline overlords claim human love for these majestic beasts is all down to infection with Toxoplasma gondii. To those sad fools who have never known the life-affirming joy of playing with a darling kitten, this seems like a plausible explanation of our collective devotion.
Residents of the real world recognize that this is, to be frank, a load of rubbish and now Illinois brain scientists have stepped in to stop the slander. They combined information gleaned from the World Population Review website’s happiness index with Toxoplasma gondii seroprevalence rates and other publicly available economic indicators, to probe the relationship between cats, happiness and neuroparasite infection rates.
The team, based at the Institute for Mind and Biology, University of Chicago, confirmed in impact neutral journal PLOS One last week, that national happiness statistics correlate with cat density. Importantly, they found that populations with high prevalence of Toxoplasma gondii were less happy.
That’s right, the more cats in your surroundings, the more likely you and your neighbours are to express contentment. In places where lab tests for the brain parasite show high rates of infection, people are less pleased with their lot.
So are countries with a lot of cats really happier and less likely to test positive for brain parasites?
The Cost of Comfort
The researchers used the results of a 2025 report by the Gallup and Oxford Universitry’s Well-being Research Centre – The World Happiness Report to determine how happy each country is. The report uses a very simple method to rank countries in terms of happiness. They ask 1000 people a single, universal question: ‘Please imagine a ladder with steps numbered from 0 at the bottom to 10 at the top. The top of the ladder represents the best possible life for you and the bottom of the ladder represents the worst possible life for you. On which step of the ladder would you say you personally feel you stand at this time?’
The self-described happiest countries are: Finland, Denmark, Iceland, Sweden and Israel. While the least happy countries with estimated cat populations are Afghanistan, Lebanon, Zimbabwe, Botswana and Zambia.
What about cats? The team say they downloaded cat ownership data from a now-defunct website ‘WorldStats.com’. Apparently, the top cat loving countries were Montenegro and Luxembourg, each with an estimated cat population of 200,000, or three cats for every 10 people. These were followed by Slovenia, the USA, Estonia and France with two cats for every ten humans. We don’t know how these numbers were calculated or from whence worldstats got them.
Happiness, GDP, Toxoplasma and Cats
The average happiness score of the top ten happiest countries is 7.3 out of 10, with an average of 1659 cats per 10,000 humans. While the ten least happy countries scored 3.4, with an average 184 cats per 10,000 people. Likewise, statistics linked both happiness and cat density scores to higher GDP, income and spending on health.
This could mean one of two things. Either cats are good at finding homes around happy people living comfortable lives, or, the happiness that cats evoke in their human caretakers drives economic success and sometimes greater aspirations. As McGill University-based expert on Ottoman military history Veysel Simşek PhD explains, an Istanbul with no cats is unthinkable for Turkish people. “I would never dare make such a claim myself, but some might argue that the rapid Ottoman expansion into the Balkans and the Middle East in 1350s to 1550s would never have been possible without the empire’s formidable feline raiders—thousands of them, all meticulously trained to bite and scratch the enemy on command. Many of these battle-hardened veterans eventually retired to Istanbul, where they enjoyed generous military pensions, paid in food, milk, and well, mice of the city. The famous Istanbul cats today are the grandchildren of those warriors. As one classical Ottoman poet described his own cat:
‘Great fighter, he even turned the lion’s life into hell; Soldier of faith, he’d kill mice as though they were the infidel.’ (Mealî (d. 1535/36), translated by Talât Sait Halman) Clearly, the contribution of cats to Ottoman military achievements remains a scandalously understudied subject.”
But surely with all those cats around Toxoplasma gondii infections must be sky high? Interestingly, according to the authors of the paper, this was not the case.
We Can’t Allow Science to Undo Its Own Good Work
The team made a rather interesting claim: human Toxoplasma gondii infections were negatively correlated to cat density. The more cats per 10,000 people, the fewer people who would test positive for antibodies against the neuroparasite. The researchers looked at the number of folk expected to show evidence of long-term exposure to Toxoplasma gondii in the form of IgG antibodies, and more recent infections flagged by IgM antibodies.
They got hold of these statistics by scraping it from another research paper. This paper attempted to estimate toxoplasmosis prevalence in the general population from pregnant women’s blood test results. In cases where they found no data from pregnant women, the authors used statistical modelling to make up a figure that sounded reasonable based on their neighbours.
It’s not routine to get a blood test for Toxoplasma gondii. In fact in some countries, including the UK, Canada and the USA government bodies advise against it. This means data is scarce, especially in countries like Afghanistan that aren’t known for high-tech maternity care. Toxoplasmosis is more common in hot countries, where the parasite can survive waiting for a new host. What’s more, most cases come from eating undercooked meat. Without adjusting for the likelihood that people were exposed to the parasite through their diet, we can’t exclude a positive correlation between the number of cats in a country and toxoplasmosis rates.
The researchers also found that Toxoplasma gondii infection rates negatively correlated with happiness, health expenditure and GDP. You can draw your own conclusions about cause and effect.
I Claim the Right to Be Unhappy
Unfortunately, as you may have noticed, the sources for these statistics are perhaps not what you might call reliable. Regardless of how well done the analysis is, if the input data is questionable, the whole exercise is pointless. We can’t make any conclusions based on the Toxoplasma gondii numbers other than people in hot countries are more likely to have it.
Israel and Lebanon, for example, have similarly high rates of recent toxoplasmosis, but are at opposite ends of the happiness scale. Israel has nearly twice as many cats as Lebanon per capita, according to the paper.
It dopes seem reasonable to say that there is not a noticeable upswing in Toxoplasma seroprevalence in countries with more cats and people in those countries rank themselves as more content.
Is it really possible to show that possible that the bump in mental well-being touted by people in cat-loving cultures isn’t actually caused by a neuroparasite? My instinct says absolutely.
Is it plausible that millions of humans are being mind tricked into seeing sadistic hell gremlins as more precious than a human baby by a single-celled organism. I have my doubts. But what do I know? Sorry, gotta run. Sounds like the litter tray has just been cleaned…
– By Beans Mulvaney-Fung
Sources
Helliwell J, Layard R, Sachs J, De Neve JE, Aknin L, Wang S. Executive Summary. In: University of Oxford; 2025. doi:10.18724/WHR-NKM9-5M31 World Happiness Report
Global, regional, and country seroprevalence of Toxoplasma gondii in pregnant women: a systematic review, modelling and meta-analysis | Scientific Reports. Accessed October 6, 2026. https://www.nature.com/articles/s41598-020-69078-9
Frequently Asked Questions. Accessed October 6, 2026. https://worldhappiness.report/faq/
Borráz-León JI, Rantala MJ, Krams I, Maestripieri D. Wealth, health, cats and Toxoplasma gondii: An ecological correlational study of subjective well-being across 93 countries. PLOS ONE. 2026;21(9):e0357911. doi:10.1371/journal.pone.0357911
