‘Human personality is a broad spectrum, and there will always be those willing to do whatever it takes. However, the hypothesis positing a parasite-based alternative is fun to consider. It’s speculated (one person has speculated it) that the ‘alpha dog’ business mentality may be a side effect of Toxoplasma gondii, a parasitic microorganism that spreads through any number of varied animal hosts and influences their behavior in odd but ultimately self-serving ways. Infected wolves are more likely to break away from packs and go it alone… and apparently, infected humans are more likely to major in business and start their own companies. Does it sound a bit baroque? Absolutely. But when you look at the recent business decisions of Elon Musk, it seems plausible brain parasites might be at play……’
— via Boing Boing
I’ve written before about my fascination with Toxoplasma infection: here, here, and here, for example, if you want to delve further into the issue.