Is it a cause, is it an effect, or is it a self-selection process?

good point

What about ex smokers?

Mentally crippled for life.

I've actually read a study claiming the opposite in the past... that nicotine in tobacco can help prevent neural damage and illnesses such as alzheimers.. it was actually pretty interesting.

The real retards are the ones that believe every fucking study they read. In the 50's more than half the population smoked (and 2nd hand smoke was everywhere) yet the cancer rate was about 1 in 10, now less than 25% of the population smokes and now 1 in 3 will get cancer and by 2020 it will be 1 in 2. Me thinks its you fucks that worry about every little damn thing killing you that are the real cause of cancer.