A few years ago, I was at a conference in Aspen for leaders and founders. As we were walking to dinner, a few of them split off to stop at a local cannabis shop. It was the first time I’d ever seen anyone legally buy marijuana, and I started to wonder what impact it was having on their work. When I asked them, they said they hadn’t noticed any effects.
As a citizen, I think it’s outrageous that people have gone to jail for the possession of marijuana—it seems like a vestige of the Puritan era. Legalizing recreational use seems like a straightforward decision in a country where more dangerous substances like alcohol and tobacco have long been allowed. As a psychologist, though, I don’t think we’re talking enough about the cognitive effects. As recreational use becomes increasingly legal,
In the Netherlands in 2011, the city of Maastricht attempted to solve a drug tourism problem by limiting cannabis purchases to Dutch, German, and Belgian citizens. A pair of economists, Olivier Marie and Ulf Zölitz, realized this was a natural experiment that would allow them to track the impact on college and graduate students’ academic performance.
It turned out that when students were banned from buying weed, their grades improved significantly (11% of a standard deviation), and their odds of passing a course climbed (from 74 to 78 percent). The benefits were especially pronounced among younger students and in quantitative courses.
Interestingly, it wasn’t effort that drove the performance gains. Students didn’t spend more time studying after they couldn’t buy pot. Instead, it seems that their focus of attention and comprehension improved. They reported understanding course concepts and lectures more clearly.
Of course, it’s possible that students might be more susceptible to the cognitive effects of marijuana. In a new study, researchers recruited several hundred entrepreneurs, invited them to generate new startup ideas, and had independent experts rate their creativity. Cannabis users generated ideas that were more novel—but less practical. This is consistent with the notion that marijuana use lowers attentional filters, which can help with the divergent thinking to develop original ideas but undermine the convergent thinking necessary to judge feasibility and develop them into plans worth executing. And the pattern of novel but impractical were especially pronounced among cannabis users with high levels of entrepreneurial passion. Having your head in the clouds appears to be more than a figure of speech.
As COVID vaccines have been rolled out, people have increasingly exercised their rights to know the consequences of injecting a foreign substance in their bodies. Shouldn’t we also be curious about understanding the impact of inhaling marijuana into our lungs?
It’s surprising that we’re doing so little to study the implications, let alone communicate the knowledge that already exists. We have plenty of guidance about the amount of alcohol consumption that’s healthy, but virtually nothing to help people make informed decisions about recreational marijuana use. That seems especially critical for a group of leaders and founders who are responsible for the livelihoods of their employees and their customers. I’d love to make sure they’re not full of ideas that are only half-baked.