They discuss it briefly and it turns out the above commenter is 100% correct in his assessment. Relevant quote from the paper:
>Given the correlational nature of the study, observed patterns may not be causal; for example, higher risk-takers could be more likely to be both entrepreneurial and exposed to T. gondii [...], thereby driving the correlation.
Remember that while it might sound amazing that a parasite could steer higher cognitive functions towards something as abstract as being more entrepreneurial, there is no practicable mechanism suggested so far and until someone figures out if it is even possible, all these studies are to be handled with care.
> there is no practicable mechanism suggested so far
There is, actually. T. Gondii has the genes to make tyrosine hydroxylase which is a dopamine precursor. It also visibly modifies rodent behavior around cat urine. Robert Sapolsky is one of many researchers narrowing in a mechanistic model of how parasites can influence host behavior.
Steering higher-order behavior by modifying reward circuits is possible and overtly practiced in many types of (mostly superficial) human relationships, organizational interfaces and societal structures.
The situation is by far not as clear as you would suggest here. The dopamine gene for example was shown to have no effect on neurochemistry in mice [1]. Even on the surface, there's a lot more to possible Toxo induced behaviour changes than just dopamine, as evidenced by neuroinflammation or cysts in the amygdala. Noone has figured out how these things actually work so far. And diminished fear response to smells in mice is a long way from general entrepreneurialism in wolves.
