there is plenty of evidence that regular use/abuse of pot (especially starting at a young age) does lead to a disproportinate percentage of violence.
chemicals do effect behavior and personalities. ultimately, however, i agree that the individual is responsible.
I think people miss the point when talking about this subject. 007 drinks alcohol and he's cool. Cheech and Chong as well as Bob Marley are cool because they are into cannabis.
People see movies like:
Days of wine and roses
Lost weekend
Panic in Needle park
Requiem for a Dream
Candy
Clean and Sober
And they react one of 4 ways.
1) Drugs are bad
2) Drugs expand your mind. They numb your pain thus making you stronger and more able to endure hardship. They are good because they allow you to travel beyond your natural abilities.
3) Drugs aren't bad, people are bad
4) Drugs make good people bad, and bad people worse.
I was lucky to be born a nerd. I was a kid and this stuck with me.
PIKE: Did they ever live on the surface of this planet? Why did they go underground?
VINA: War, thousands of centuries ago.
PIKE: That’s why it’s so barren up there?
VINA; The planet’s only now becoming able to support life again.
PIKE: So the Talosians who came underground found life limited here and they concentrated on developing their mental power.
VINA:
But they found it’s a trap, like a narcotic, because when dreams become more important than reality, you give up travel, building, creating. You even forget how to repair the machines left behind by your ancestors. You just sit, living and reliving other lives left behind in the thought record.
Non-prescription and often prescription drugs are an admission that reality is too tough for the individual. If you
need chemicals, you're weak. That's how I always looked at it. And I never wanted to see the face of a weakling when I looked in the mirror.