Cohen's d=-0.132 is considered a very small effect size. In other words: The effect is statistically reliable, significant, and disagreements between studies are very low, but not that big.
>The approximately 2-point decline in IQ in adolescent-onset frequent
cannabis users is not to be clinically significant
In a population level this might be part of the explanation, but we would have to know the correlation between prevalence of use of cannabis and IQ decline in the population. In developed nations there is trend where IQ drops 0.2 points per year (2-points per decade) since mid 1990s. In developing countries IQ increases 3-points per decade as Flynn-Effect still works there.
Rastas say that "cannabis" isn't for stupid people, which is an observational conclusion.
There are other sometimes profound and imediate negative effects cannabis consumption
Like any tool, it depends on how you use it. As a teenager, I used it to paint and write. It opened many doors. I found inner expression that was not possible otherwise.
The measures used in the study are not absolutes and only a fragment of what constitutes human intelligence.
IQ as measured correlates positively with all talents.
There is moderate correlation with arts, sports and athletic talents (weak for basic athleticism, moderate to strong for elite levels.) With music and writing the correlation is even better, from moderate to strong. High IQ increases the ability for inner expression, or expression of any kind.
People seem to forget that IQ is a factor as in factor analysis. It does not measure a "thing". It measures variability among observed, correlated variables.
That's why all of your favorite, and history's greatest, visual artists, writers, athletes, musicians and aesthetes stay far away from any mind altering substances!
Erdos famously stayed far away from amphetamines to preserve those precious 2 IQ points.
This is a false equivalence. There is no known correlation between amphetamines and a decline in IQ. If anything, they are nootropics (they don't make you smarter but improve your short-term memory, focus, etc.). Psilocybin stimulates neuroplasticity and adult neurogenesis. Cannabis, as far as we know, does no such thing.
Cannabis is better enjoyed as a late adult, maybe >25 years old, as almost any drugs. I wouldn't advise it to the youth, it can really ruin your concentration years later.
I'm curious what kind of effect alcohol has on IQ. Alcohol is very well established to be pretty bad for brain health even if you don't always feel it.
Even proponents of IQ tests admit they have a margin of error 3-5 points. Meaning you can swing on IQ tests beyond this threshold on the same day.
I'm guessing bad sleep or missing a meal the night before will swing your IQ significantly more than 2 points.
>The approximately 2-point decline in IQ in adolescent-onset frequent cannabis users is not to be clinically significant
In a population level this might be part of the explanation, but we would have to know the correlation between prevalence of use of cannabis and IQ decline in the population. In developed nations there is trend where IQ drops 0.2 points per year (2-points per decade) since mid 1990s. In developing countries IQ increases 3-points per decade as Flynn-Effect still works there.
The measures used in the study are not absolutes and only a fragment of what constitutes human intelligence.
There is moderate correlation with arts, sports and athletic talents (weak for basic athleticism, moderate to strong for elite levels.) With music and writing the correlation is even better, from moderate to strong. High IQ increases the ability for inner expression, or expression of any kind.
People seem to forget that IQ is a factor as in factor analysis. It does not measure a "thing". It measures variability among observed, correlated variables.
Erdos famously stayed far away from amphetamines to preserve those precious 2 IQ points.
Compared to either alcohol or tobacco, the risks are minimal.
The petro mafia is preventing a transition away from oil, the alcohol and tobacco mafia are fighting the use of cannabis.
Anyone who doesn't like the effects, or has any other reason, shouldn't use it.
It certainly does much less damage to the teenage brain than instagram and the other faceplant products.
All through the 60's and 70's when cannabis use was increasing, we were still seeing a steady increase in US educational outcomes.
Ever since the iPhone and friends, and associated online shitpost websites, proliferated, we've seen a steady decline in education.