On Wed, Jan 14, 2015 at 9:02 AM, Quentin Anciaux <[email protected]> wrote:
> > > 2015-01-14 15:39 GMT+01:00 Jason Resch <[email protected]>: > >> >> >> Correlations don't prove causal relations, >> > > > I know all I point out, is that there are now many study done on that > correlation... You can dismiss them.. > My point is that correlations themselves (even when proven) are effectively meaningless. Take the supposed evidence that nutritionists used to demonize fat as leading to heart attacks. Correlations where shown between various countries that showed countries with higher fat intake had higher incidence of heart disease. But it was later shown that fat intake in countries was determined largely by the countries per capita GDP. So now you can see the correlational study (which put the blame on fat) could be explained by anything else that correlates with per capita GDP: stress, long working house, consumption of sugar, cigarette use, etc. Think of it this way: if heart attacks correlate with economic development of a country, another study might have been able to show a strong correlation between driving cars and heart attacks (because more cars are owned and more people drive in those countries). But it would have almost certainly been wrong to conclude "Drive less to avoid heart disease". Yet this is the same error that led nutritionists to the bad advice of "Eat less fat to avoid heart disease". Only a controlled study which actually tests the hypothesis can separate mere correlations and true causes. Do we know if cannabis correlates with depression because depressed people seek it to self-medicate? We might observe a similar correlation between depression and SSRI use, but we know SSRIs are used to treat depression, so it makes sense. We don't conclude though that SSRIs cause depression. If your claim is that cannabis causes depression, you need to point to a study that takes two groups of subjects, subjects one group's members to regular cannabis use and another that prohibits cannabis use among members, and then study whether the incidence of depression is higher in one group vs. the other. All science is based on "Observe, Form Theory, Test Theory". It's important that we realize all correlation studies (in all domains) are nothing but the first step "Observe". Forming policies or opinions from formed theories that haven't been tested is asking for trouble. (Just look at the current US and now world health crisis due to moving people to low-fat diets when the only basis was a correlational study (since disproved by controlled testing)). > yet they exists and they seems correctly done... maybe it's prohibitionist > agenda.. I know for myself that I can't control my cannabis usage and when > I was using, I was abusing and that certainly did not help me at that > time... But if you think cannabis abuse is a fairy tale... fine with me... > and if you think it is not, but it has absolutely no side effect... ok... I > won't agree with you but it's your belief... and I've mine. > I don't see where are you getting this from out of what I said. Jason -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
