Are people more creative under the influence of cannabis? Research design practice

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As of June 2023, recreational cannabis use is legal Canada (Department of Justice, Canada, 2021) and in 23 U.S. states, the District of Columbia, Guam, and the Northern Mariana Islands (Reuters, 2023). Not that it has to be legal for people to use it.

In a 2022 national survey, researchers asked people about their marijuana use. Of full-time college students between the ages of 19 and 22, 22.1% reported that they used marijuana at least once in the last 30 days, whereas only 4.7% reported that they used it daily. Both numbers were lower than for age-matched non-college students (28.2% monthly and 14.5% daily). That 30-day percentage of 22.1% for college students is about where the numbers have been since 2013. To see these kind of numbers for marijuana use, we have to go back to the early 1980s. In 1980, a whopping one-third (34.8%) of college students reported using marijuana in the previous 30 days (Patrick et al., 2023).

Why do college students use marijuana? In one qualitative study, one reason participants gave was that they used it for a boost in creativity (Kilwein et al., 2022). But does marijuana actually make users more creative? Or do they just think they are more creative?

After covering experimental design, give your students this hypothesis:

Cannabis use increases creativity.

Ask students for the independent variable (including an experimental group and a control group) and the dependent variable(s). For all variables, ask for operational definitions. After students have had a couple minutes to consider this on their own, ask students to work in small groups to create their experimental design. If time allows, ask students how or where they would find volunteers for their study. What are the ethical concerns that they need to take into consideration? After group discussion dies down, ask a volunteer from each group to share their design.

Now share with students how researchers investigated this same question (Heng et al., 2023). To recruit participants, researchers posted flyers in recreational cannabis dispensaries in Washington (a state where such use is legal) and on Craigslist. Users who smoked one joint no more than a few times a week were selected to participate. Anyone who reported being pregnant was excluded. Participants were mailed cannabis test kits and emailed the study information. Participants who successfully completed the study received a $25 gift card.

Participants were randomly assigned to one of two conditions: high during the creativity test or not high during the creativity test. “High” was operationally defined as having used marijuana in the last 15 minutes. The researchers note that the participants had to supply their own cannabis. “Instead of stipulating a specific time to complete the study, participants were asked to begin the study within 15-min of their volitional cannabis use. This addressed the IRB restriction of not instructing cannabis use” (Heng et al., 2023, p. 637).

Now we need an operational definition for creativity. “Participants were asked to generate as many creative uses as they could for a brick in 4 min” (Heng et al., 2023, p. 637). They also rated their brick ideas based on how creative, original, and novel they thought they were on a 5-point scale.  Then they used the saliva test kit and mailed it back to the researchers.

What did the researchers find? Participants who used cannabis before doing the creativity task thought they were more creative than did those in the control group. But were they really more creative”

The researchers asked a couple research assistants who were blind to conditions to evaluate the creativity of the answers, and they also asked participants on Prolific to do the same. Neither the research assistants nor the Prolific participants saw any difference in creativity between the groups.

There was a bit more to the research design if you’d like to share this with your students as a way to conclude this activity. The researchers also asked the participants how happy and joyful they were. The researchers found that it was this mood state that mediated creativity evaluations. Cannabis use was more likely to result in higher creativity ratings if the person was happy while high.




Department of Justice, Canada. (2021, July 7). Cannabis legalization and regulation.

Heng, Y. T., Barnes, C. M., & Yam, K. C. (2023). Cannabis use does not increase actual creativity but biases evaluations of creativity. Journal of Applied Psychology, 108(4), 635–646.

Kilwein, T. M., Wedell, E., Herchenroeder, L., Bravo, A. J., & Looby, A. (2022). A qualitative examination of college students’ perceptions of cannabis: Insights into the normalization of cannabis use on a college campus. Journal of American College Health, 70(3), 733–741.

Patrick, M. E., Miech, R. A., Johnston, L. D., & O’Malley, P. M. (2023). Monitoring the Future Panel Study annual report: National data on substance use among adults ages 19 to 60, 1976-2022 (Monitoring the Future Monograph Series). Institute for Social Research, University of Michigan.

Reuters. (2023, June 1). U.S. states where recreational marijuana is legal. Reuters.



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About the Author
Sue Frantz has taught psychology since 1992. She has served on several APA boards and committees, and was proud to serve the members of the Society for the Teaching of Psychology as their 2018 president. In 2013, she was the inaugural recipient of the APA award for Excellence in the Scholarship of Teaching and Learning at a Two-Year College or Campus. She received in 2016 the highest award for the teaching of psychology--the Charles L. Brewer Distinguished Teaching of Psychology Award. She presents nationally and internationally on the topics of educational technology and the pedagogy of psychology. She is co-author with Doug Bernstein and Steve Chew of Teaching Psychology: A Step-by-Step Guide, 3rd ed. and is co-author with Charles Stangor on Introduction to Psychology, 4.0.