The 9 Biggest Lies About Marijuana Legalization

7. Smoking Pot Lowers Your IQ

Pot smokers having lower IQ’s is an age old stereotype. The claim has been used to argue against marijuana.

A 2012 study from Duke University found a link between heavy marijuana use and IQ decline among teenagers.

The studies findings were immediately questioned, and within six months the same journal published that their “methodology is flawed and the causal inference drawn from the results” was “premature.”

However, they wouldn’t completely discredit their former results without further evidence.

As a result, several studies that contradict the journals original claims have been published across the world.

In one study, 2,000 groups of teen twins were observed. One sibling would smoke weed and the other would not.

Afterward they tested their IQ’s and found the marijuana-using twins had lower IQ scores.

However, they don’t link the decreased IQ to pot use. They found other factors more likely to be impacting their IQ.

A U.K. study conducted at the University College of London found the relationship between teen pot use and IQ was non-existent.

They studied 2612 children born in the Bristol area of the U.K. in 1991 and 1992.

Even heavy marijuana use wasn’t associated with individual IQ. The study found “no relationship between cannabis use and lower IQ at age 15.”

They found other factors that more clearly caused a decline in IQ scores.

“In particular alcohol use was found to be strongly associated with IQ decline,” the authors wrote.

Unfortunately, you rarely hear about alcohol’s effect on IQ.