In the past few weeks the whole nation has been flooded with countless reports claiming the effects that marijuana has on the brain. Apparently, it was reported that those who started taking marijuana in their teenage years when their brain is still developing experience lower cognitive ability in their adulthood, scoring significantly lower on cognitive tests when compared to those who started partaking in their twenties or later in life.
One scientist, however, Lior Pachter claims that the research report submitted was very flawed. He admitted that he himself didn’t smoke pot or use any other drugs, and after examining the research submitted thoroughly was able to find quite a few holes in their methodology, and additionally, found a misinterpreted conclusion which they released to the media.
After examination, Pachter suggested that the researchers involved in the study cherry-picked their data to meet their conclusion.
It was similar to ‘confirmation bias’, a research flaw involving already having a conclusion, and involves testing and using hypothesis and raw data that only supports your claim. Pacther believes that the researchers were somewhat influenced by a similar problem when conducting their study.
Pachter also points out that the study only shows correlation and not casualty. Meaning, that while there was an association between the lower function of the brain and the use of marijuana in earlier life, it does not mean that it is that which cause it.
Pachter goes further to say that in the research, they’ve already come up with the conclusion, and were simply testing over a long period of time until they were able to find the correlation that they needed to confirm their hypothesis. He points out that “maybe users have strange brains because they smoked pot. However, it might be just as possible that these users smoked pot because they had strange brains.”
The scientist warns about not believing everything that you read, and how sometimes, researchers may misinterpret information, accidentally or intentionally, to come to a conclusion they want. Data interpretation is easily manipulated, and we should become more skeptical concerning everything we read in scientific journals, and even more so, the internet.