Quote:
Originally Posted by
Flambeur 
Do people ever wonder why after 1000s of years of walking under the sun, it's all of a sudden bad for us? Just saying. Cigarettes are a whole another thing, but the two are actually related in the fact that there are groups of people more predisposed to getting negative effects from either tanning or smoking.
Because for those thousands of years, people were not
literally under the sun. It's the proximity that does the damage. Case in point, it's my understanding that airline pilots have higher incidences of cancer simply due to the fact that they are exposed to more and stronger cosmic radiation than normal. They're not all that much higher up in a cosmic scale, but it already makes a difference.
On the predisposition issue, again it's the fact that genetics may play an underlying role, but you still need to trigger it. There's no guarantee that those genes won't set off on their own, but by doing something like tanning, you're playing with fire. In other words, just because "it's in my genes" doesn't make it inevitable. That's oversimplying things. We're quick to blame genetics when there are so many other behavioural triggers that we can avoid. You only hear of the people who die of lung cancer who don't smoke, for example, in the same way you think flying is dangerous. You only hear of the exceptional cases, the outliers. You don't hear about the guy with predisposition for lung cancer, who died of lung cancer but who could have avoided it had he not smoked at all, because no one would ever know if that's true or not.