Studies of a group of kids in New Zealand have found quot;that early-onset cannabis use is more common for those with poor self-control, prior conduct problems, and high scores on risk factors correlated with a low family socioeconomic standard,quot; he says. So, Rogeberg simulated how these factors could have caused the IQ drop that the original researchers saw. His analysis was published today, Jan 14, 2013, in the journal Proceedings Of The National Academy of Sciences. He found that most, if not all, of the effect seen in the original study could be accounted for by the low socioeconomic standard factor. These kids with lower socioeconomic status are less likely to be put into intellectually challenging environments, which are part-and-parcel of an increasing IQ score throughout life. Though the original study, by Madeline Meier, et. al, claims to have controlled for socioeconomic standard, Rogenberg says his new analysis indicates that this could have created the link they found between IQ and weed use. - Business Insider
