Researchers with the University of British Columbia set out to see if there's any truth to the stereotype that smoking weed causes laziness. And surprise (!): According to the UBC study, there is. Using lab rats, the researchers found that when high, stoned rodents opted to perform less challenging tasks than when they were sober.

In the study, published on Tuesday in the Journal of Psychiatry and Neuroscience, researchers trained lab rats to perform a more cognitively engaging activity for a bigger reward as well as a less challenging activity that would yield a smaller reward. When the rats were sober, the study found that they tended to opt for the more difficult task and the greater reward, but when they had marijuana in their systems, the rats went with the less demanding task even though it meant less of a reward.

The researchers also discovered that, while the rats were still able to perform the harder task while stoned, they simply didn't want to deal with doing it while they were buzzing. 

The study's authors looked at whether or not CBD—the chemical in marijuana that pot researchers believe helps relieve pain and that has been used in treatments for epilepsy and cancer—could block the cognitive impacts caused by THC, the chemical in marijuana that produces psychoactive effects. In their study of the 29 rats, the UBC researchers did not find that CBD blocks or mitigates impacts of THC.

The study's senior author Catharine Winstanley, who is an associate professor in UBC's psychology department, said in a press release that the CBD findings are cause for concern, given that motivation is a key factor for achieving success and could be an obstacle for people who use marijuana.