First, let us assume that intelligence and common sense is a genetic trait. If this assumption turns out to be true, then we may find human beings are improving themselves through smoking, or more accurately, smokers are helping are helping the rest of the human race. You see, people who are raised by smokers are 90% more likely to smoke. If two "bad choice makers" start smoking, and have children, it is likely that the majoirty of those children will start to smoke. If those children smoke, it is also likely their own children will start to smoke. Considering family holidays, the amount of second hand smoke that children would breath would be enormous on days such as thanksgiving and christmas, and the rest of the time, the children would be breathing in their parents smoke, and would subsequently be more likely to smoke themselves, upping their chances of dying at a younger age. Which slowly will widdle away the population, and keep the population in check. We all know it's true even if we don't want to admit it.
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Slightly skewed logic. The U.S. by itself is not really having any problems being overpopulated, you know. Maybe the big cities are crowded, but in states like Wyoming, there are enormous amounts less of people per mile. But hey, if that's how you want to justify smoking, than keep on truckin. I have a feeling you wouldn't be singing the same tune (or singing period) if you were the one dying of lung cancer.
~I don't smoke. There are cooler ways to die.~
China is a bit overpopulated, and is the biggest buyer of cigarettes in the world. I betcha it's doing them a world of good. (Plus, if the u.s goes to war with china, the Marines would always be able to out run the chinese now.)
"It's Better To Burn Out Than To Fade Away" -Neil Young
OK just a little comment on your if the parents smoke then most likely the kids will. Well my grandparents BOTH smoke they have 8 kids and none of their kids smoke. So there goes that. I can walk outside and get shot before I die from smoking. Don't take this as me being mean or anything but I am sick of people talking about smoking like this. If you don't smoke great fro you that is your choice. If you do smoke great for you that is your choice.
Smokers in Africa drive off mosquitos so fewer die of malaria.
Smoking also prevents some parasites.
Smoking also dulls the apetite so those Chinese soldiers can operate longer on less food than American marines. They are also likely to be narrower and harder to hit with gunfire.
The other problem with your theory is that the death brought on is not only too slow to prevent reproduction of smoking offspring, but also some people never succumb to the diseases at all. Thus there is the chance of a super smoker race being bred long before the trait is eliminated.