Toxoplasmosis has been pointed out as a strong indicator whether or not someone is Rh negative. Both, Rh negatives and Rh positives, appear to be affected, but in very different ways.
Rh negatives tend to suffer strongly from a loss of coordination which can lead to increased risk when operating machinery. Rh negatives tend to also experience a boost in mental performance showing in higher IQ test results among Toxoplasma-gondii-infected Rh negatives vs. uninfected Rh negatives.
In Rh positives, being infected tends to lower IQ scores.
Many reports have lately associated Toxoplasmosis with risk-taking and entrepreneurship. ABO and Rh factor related details have not been published in such articles.