Brain Parasite Theory of Entrepreneurship

As always, we should take new theories with a grain of salt. In this case, you might get a little grossed out!

The Toxoplasma gondii parasite is carried by felines (cats) and has be found to infect their human masters too. The parasite can be caught through contact with the animals and their bodily fluids and solids. The parasite causes brain cysts that last a lifetime and lead to behaviors including bipolar disorder, reduced fear, and lower IQ.

Some have estimated that over 2 billion humans have been infected, though infection rates differ greatly by country. For instance, the U.S. infection rate is around 3%, while it may be as high as 50 to 70% in France and Mexico. Petr Houdek at University of Economics in Prague reviewed the literature in a 2017 paper published in the Academy of Management Perspectives.

Research by Stefanie Johnson (Leeds School of Business) and colleagues (a gang of non-biologists) suggests that those infected by the virus are 1.7 times more likely to choose entrepreneurial career paths. They test subjects for infection by taking saliva swabs. They find significant positive associations between infection and entrepreneurial activity and intention, and a significant negative association with fear of failure.

The explanation for this change in behavior is due to the association between a Toxoplasma Gondii and an increase in testosterone levels (Zouei et al., 2018). Research suggests that higher testosterone levels is associated with greater risk-taking behavior and entrepreneurial intent in humans (Bönte et al., 2016).


A recent control group study by Lerner et al. (2020), was conducted on 16,068 female founders from 11,433 startups and found that there were multiple links between the Toxoplasma Gondii and entrepreneurship thus replicating the results of Johnson’s (2018) study. Lerner et al., go on to state that the infection of the parasite precedes entrepreneurial ventures meaning that individuals are significantly more likely to pursue a new venture following a Toxoplasma Gondii infection. 


This research is pretty new and should be replicated several times before budding entrepreneurs decide to expose themselves to felines voluntarily.


This research is pretty new and should be replicated several times before budding entrepreneurs decide to expose themselves voluntarily.

Our book is now available on Kindle.