One in five or more of you reading this article are likely to be infected with toxoplasmosis. You probably caught it from a cat but it doesn’t make you feel obviously ill. It does, however, make you behave differently. Two papers published this year support the idea that this common brain parasite can even make us vote differently. Infection makes you less cooperative and a bit more aggressive, which in wolves makes them more likely to become a leader. In humans it manifests as changes in levels of aggression and antisocial behaviour but ironically, can make you more successful as a businessperson. Is your cat making you more conservative? Could be. But why does this happen? And why do relationships like this even exist in nature? This is a wonderfully left-field example of how much we depend on other wildlife … and are part of it. We cannot live alone and we have only the faintest grasp on our own species’ fate.
Cats use mind-control to rule dogs
Cat-owners will already know that cats are capable of mental mind-control but I’m afraid it’s worse than that. Scientists looked at 22 years of blood data involving over 200 wolves in Yellowstone. Wolves that spent time near cougars (cats) were more likely to be infected by toxoplasmosis. This meant that:
- Both male and female infected wolves were more likely to leave their pack earlier than they normally do;
- Infected males were an amazing 46 times more likely to become pack leaders than uninfected males!
This type of parasitic mind control is not unusual in the animal world. It’s only fairly recently that scientists have been seeing an uptick in toxoplasmosis in humans. As Imperial College London scientists Joanne Webster says in this article in Discover Magazine says:
“We often see symptoms like altered activity levels, changes in risk behaviours, and decreased reaction times … but in some cases, they become more severe — like schizophrenia.”
Toxoplasmosis infection risk in selected countries from Flegr et al. 2014
- Australia, 23%
- Canada, 20%
- Costa Rica, 76%
- Czech Republic, 20%
- France, 54%
- Indonesia, 53%
- New Zealand, 35%
- Norway, 11%
- Papua New Guinea, 18%
- USA, 11%
- UK, 9%
Wolves and world leadership
It’s hard to know for sure but it would seem the real Wolf of Wall Street, Jordan Belfort, has a soft spot for animals. Latest ventures include a blockchain-based pet company. I’d bet he grew up around animals and probably cats.
It is quite well known that toxoplasmosis creates business people and entrepreneurs. A study in 2018 found that:
- Students who tested positive were 1.4× more likely to major in business;
- Professionals attending entrepreneurship events who tested positive were 1.8× more likely to have started their own business compared with other attendees; and
- Nations with higher infection had a lower fraction of respondents citing ‘fear of failure’ in inhibiting new business ventures.
Less well known is the effect this has on our political behaviour. For starters, leaders are more likely to carry the parasite. We know that already. But what about the rest of us? Is your cat making you more conservative? It seems very likely.
Toxoplamosis and how it affects our attitudes to others
This 2022 study in Evolutionary Psychology looked at a sample of over 2,000 Czech men and women.
According to the studies authors as reported in Psypost Magazine, ‘men and women infected with the disease demonstrate lower conscientiousness, generosity, and novelty-seeking’ but this is also associated with worse health. People with toxoplasmosis were less loyal, less liberal and had a tendency to be anti-authority. The change in behaviour is thought to be to do with inflammation of the brain.
For the most part this is quite benign and only at the extremes do we see the worst behaviours emerging. Makes you wonder about some of our worst dictators doesn’t it? And why is there always a cat in Number 10 Downing Street?
Cooperation can’t exist alone
So, if a parasite can lead to lower over health, greater anxiety and make people less cooperative, how can it exist at all? Evolution has an answer.
The subject of cooperation in nature is a theme in my book Wildlife in the Balance. I’ve also just read and reviewed Kristin Ohlen’s Sweet in Tooth and Claw. Ohlsen covers the relationship between people and microbes, the majority of which are good for us. Your gut fauna is an example. The simple fact is that cooperation is what enables populations to survive. The more aggressive and dominating portions of society die out fast.
So how can less cooperative behaviours persist, and why? If toxoplasmosis makes people less cooperative, what role does it play in nature?
At its simplest, conflict drives society forward. The least cooperative die out fastest but the cooperative portion of society would stagnate without something to struggle against. Another way of saying this is: the battle that socially woke [here I use the real world definition] people perform each day for a more just society could not succeed without something to fight for. The people they are fighting, however, rely entirely on the socially progressive, loyal, peaceful and cooperative ‘tribe’ to survive.
This is perhaps why men tend to be more aggressive than women. It could also be why toxoplasmosis benefits from existing in the ‘back of our minds’ so to speak. Don’t worry. Being infected with toxoplasmosis isn’t necessarily going to make you into a despot. Reality is, the world is a kaleidoscope of different overlapping values and cultures. You may have been chosen, by chance (or more likely by a cat). If you’re a bit more aggressive than most, you function(Of an ecosystem). A subset of ecosystem processes and structures, where the ecosystem does something that provides an ecosystem service of value to people. More as part bigger ecosystem processes you aren’t even aware of.
Did a parasite just domesticate us?
It’s absurd to think that a parasite of our brain might exist to create aggression and in doing so, help our society to survive. It’s also remarkable that our relationship with another animal can be so influential.
Cats have been part of our culture for tens of thousands of years. Ancient Egyptians thought cats had divine energy. It turns out, they had toxoplasmosis. But 10,000 years would have been long enough for cat-owners to become more successful business people. Revering cats became a case of group-natural-selection where the more cooperative animals survived together. In this case, a cat, human and parasite.
We cannot escape the fact that we are completely connected to nature (often in ways that are somewhat unsavoury to think about).
Humans don’t have control over how we behave and our society is a mere vehicle for ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More. Did we domesticate cats. No. If anything, a parasite domesticated us, connecting us to cats. That relationship endured because it was the most likely to surviveDarwin’s theory how species are formed, where those that stand in closest competition with those undergoing beneficial modification and improvement, will go extinct faster. Natural selection is by survival of the likeliest, not survival of the fittest. The fittest are only likely to survive because they happen to be most suited to the environment into which they are born. The More.
Perhaps knowing this we should take ourselves less seriously. Cats and their parasites became part of our environment tens of thousands of years ago and will remain so for a lot longer. Animals, including wildlife, have always had a huge impact on our survival. It’s time we started realising we cannot survive without them.
