Sorry if it was implied that I thought it was scientific or accurate. My comment was intended to be sarcastic. Every now and then people drag out these weird, "this is why Genghis Khan was so successful" stories.
Guess what, there wasn't a single reason and it was a multitude of reasons and whoever tells you they found the main contributing factor is more likely to just want more attention than they'd get with a more mild version like "this contributed to it".
