Addicted to Self-Harm

I just heard a piece on the radio about tanning salons in Canada. It seems that due to the potential harms caused by tanning, the forces that be have decided to regulate tanning studios in the same manner as cigarettes and alcohol - by creating a minimum age policy.

Obviously as a physician, anything that decreases the number of people who choose to artificially bake their skin seems like a good idea to me. However, this certainly gets me to wondering why such regulations are even necessary? Is the fear of cancer seriously not enough? Clearly not. For I have seen, on more than one occassion, patients who are in hospital due to lung diseases caused by smoking, who insist on continuing to go outside for their cigarette fix multiple times a day.

Why are we so addicted to harming ourselves? Yes, in the case of cigarettes, alcohol, heroine, whatever - these substances are chemically/physically addictive. But in other cases of self-harm - gambling, overeating, electing George Bush twice in a row, and yes, even tanning - there is no such confounder. So why do we do it?

The way I see it, we've either lost hope in our ability to have a more meaningful life, and therefore have just decided to choose hedonism over health and longevity. Or we have become so spoiled by the technology and the access to health care we enjoy, that we just figure we can do whatever we want, and someone else will clean up the mess.

Either way, the fact remains that we are the only species that will knowingly do things that harm ourselves and kill us sooner. Isn't evolution supposed to make smarter?