I hear this so often without any other evidence to refute an argument.. Causation requires correlation. It's certainly not enough to prove causation, but it's

I hear this so often without any other evidence to refute an argument.. Causation requires correlation. It's certainly not enough to prove causation, but it's actually a necessary starting point. Speaking of driving and marijuana, I've noticed a large increase in pot smoke coming from cars in traffic since marijuana was legalized in CA. I expect some of that to come from passengers, but people driving while high is no joke.