A new study has found a link between a parasite in cat feces and entrepreneurial behavior.

Humans can be infected with Toxoplasma gondii if they come into contact with cat feces or contaminated products, but most people do not show any symptoms.

Researchers found that students with toxoplasmosis were 1.4 times more likely to be a business major than those who weren't.

Among professionals who attended entrepreneurship events, those who tested positive for the parasite were 1.8 times more likely to have started a company.

A parasite found in cat feces may have an influence on risk-taking and entrepreneurial behavior, a team of researchers has found.

The study, published Wednesday in the journal Proceedings of the Royal Society B, found that university students who tested positive for the parasite Toxoplasma gondii were more likely to major in business, and professionals with the parasite were more likely to start their own business.

Humans can be infected with T. gondii if they consume undercooked, contaminated meat or drink contaminated water, according to the Centers for Disease Control and Prevention. People can also get the infection — known as toxoplasmosis — through contact with cat feces that contain T. gondii.

Stefanie Johnson, lead author of the study and an associate professor of management at the University of Colorado Boulder's Leeds School of Business, said the results indicate a positive correlation between exposure to T. gondii and entrepreneurial behavior. Johnson and her fellow researchers also found that countries with a higher prevalence of the parasite had a lower proportion of people who cited "fear of failure" as the reason they were discouraged from starting a business.

“We can see the association in terms of the number of businesses and the intent of participants, but we don’t know if the businesses started by T.gondii-positive individuals are more likely to succeed or fail in the long run,” Johnson said in a press release. “New ventures have high failure rates, so a fear of failure is quite rational. T.gondii might just reduce that rational fear.”

The researchers point out that most research in economics has relied on rationality as an explanation for human behavior, but biological factors like parasites have rarely been studied in connection with business choices. They suggest that behavior-altering infections like toxoplasmosis could influence human decision-making.

Infection patterns among students and professionals

Johnson's team selected 1,495 undergraduate students in biology and business classes and tested them for the presence of T. gondii antibodies. Of the group, 22% tested positive.

Results from the antibody test were then analyzed against each student's reported major. For those majoring in business, Johnson's team also compared students on the management and entrepreneurship track to other specializations like accounting and finance.

The results indicated that the students who tested positive for T. gondii were 1.4 times more likely to be a business major than those who weren't infected. Among the business majors, students who tested positive were 1.7 times more likely to be focusing on management and entrepreneurship.

Toxoplasma gondii parasite. Ke Hu and John Murray/Wikimedia Commons

Johnson's team also collected saliva samples from 197 people who attended entrepreneurship events, and each person was asked whether they had started their own business. The scientists found that the participants who tested positive for the parasite were 1.8 times more likely to have started a company.

The researchers later attempted to test for connections between T. gondii and entrepreneurship on a global level. They compiled data on the prevalence of the infection in 42 countries and compared them against national surveys of entrepreneurial activities and attitudes. The researchers saw a positive correlation between the presence of toxoplasmosis in a population and the proportion of people who reported an intention to launch their own business or were engaged in entrepreneurial activity.

Meanwhile, there was a negative correlation between the prevalence of toxoplasmosis and the percentage of people who said they were discouraged from starting a business due to fear of failure.

Johnson told NBC News that her team plans to continue this research, and look at a possible link between toxoplasmosis and conservatism next. Johnson said she also wants to test whether successful entrepreneurs are more likely to have been infected with the parasite.

“So what if all the businesses started by toxoplasma-positive people fail? What if that fear was a good thing? We want to know," she said.

The parasite has been found to influence human behavior before

More than 2 billion people, including 60 million in the United States, are estimated to be infected with T. gondii, though very few show any symptoms. According to the CDC, some people with toxoplasmosis may feel flu-like symptoms like swollen lymph glands or muscle aches. Severe toxoplasmosis may include damage to the brain and eyes, such as reduced or blurred vision.

It's still unclear exactly how toxoplasmosis influences human behavior. But past studies of populations with varying levels of toxoplasmosis have linked higher rates of the infection to more economic prosperity and higher levels of neuroticism.

Small studies conducted in the Czech Republic and Turkey also found that people with toxoplasmosis had a higher rate of car accidents.

A 2012 study analyzed decades of health records from women in Denmark to investigate the link between toxoplasmosis and mental illness. The results suggested that women who tested positive for the parasite had a higher rate of suicide attempts. The likelihood that an infected woman would attempt suicide in a particular year was 1.5 times higher than among uninfected women.

Teodor Postolache, the lead author of that study, told NPR in 2012 that the parasite may be interfering with people's prefrontal cortex.

"That area is like a braking mechanism, like it's a brake in a car," Postolache said. "That what we are thinking is that it's possible that the parasite, in fact, interferes with the capacity of the prefrontal cortex to apply brakes."

A Toxo cyst in a mouse brain. Public Domain/Wikimedia Commons

How much is our behavior impacted by parasites and infections?

It's important to note that the findings of the new study are correlational, not causal, so the authors cannot say whether toxoplasmosis caused anyone to take more risks, be more inclined toward entrepreneurship, or feel less afraid of failure. Many other factors or dynamics could be at play.

But the research adds to a growing number of studies that have shown how parasites can affect human behavior. Other studies have demonstrated how infections can influence people's susceptibility to mental disorders and other behavioral changes.

For example, Chlorovirus ATCV-1, a virus typically found in green algae in lakes and rivers, may affect people's cognition: infected people seem to have shorter attention spans and are slower to complete tasks like drawing a line that connects a sequence of numbers.

Scientists have also found links between some intestinal bacteria such as Bacteroides and Prevotella and higher levels of anxiety and irritability.

This growing body of evidence may indicate that parasitic infections could be affecting our culture and business on a larger scale than we'd previously realized, the new study says.