"In the US , the rate of infection among men in Washington DC is well over 100 times higher than in North Dakota, the region with the lowest rate. That is in one country. How do you explain such differences?"
If they can't figure out that it's behavioural, they'll never know anything.
Men can control their behavior, and won't get these diseases. Animals, on the other hand, cannot control their behavior.
That's another difference between Men and animals.
There are probably many diseases I never contracted, because I controlled my behavior. Cirrosis of the liver is one I missed too. Never shared a dirty needle with anyone, so I havn't contracted hepatitis. I don't hang with lepers, so, I missed leprosy too. Unfortunately, I did hang with the wrong crowd in high school, which made me study less than I should have then, and gave me the disease of ignorance for a while, but I was able to later recover from that. For the most part, the behavior one chooses to engage in are what make or break a person. Studying the law and passing the bar or studying medicine and becoming an MD, or studying engineering and building bridges are other behaviors, that generally gets one farther than not. If Barack O'bama could do it, then, isn't America truly the land of opportunity ? Nothign holds people back than themselves. Alexander Hamilton was a bastard child ! Look how far studying got him. Booker T Washington and George Washington Carver, Bill Cosby and many more africans have proven that race is not a factor. It's all in the behavior one chooses to engage in.