Many people hold the belief that using marijuana can help one think creatively and see the world in different ways. Over the years, various celebrated “forward thinkers”— such as Apple co-founder Steve Jobs—have credited marijuana with enhancing their creative thinking abilities. This is a particularly common viewpoint among people who consume marijuana regularly, and this altered thinking is part of the appeal for many users.
However, a new study form Leiden University in the Netherlands suggests that this boost in creative thinking is an illusion. This research concludes that while individuals may believe that their thoughts and ideas are expanding under the influence of marijuana, their creative thinking is actually unchanged or even diminished.
Subjects Tested With Different Levels of THC
To complete the study, the Leiden researchers administered either THC or a placebo to three different groups of 18 subjects. One group was given a high dose of THC (tetrahydrocannabinol, the primary psychoactive component of marijuana), one group was given a low does of THC and the third group was given a placebo.
The THC was administered through a vaporizer, and neither the groups that received THC nor the group that received a placebo were aware of what they were taking. However, for ethical reasons the researchers only selected subjects who were already marijuana users. The participants were asked to abstain from marijuana use in the days leading up to the study so that the quantity of THC in each person’s system could be managed as closely as possible.
Tasks Test Divergent and Convergent Thinking
The subjects were then given a series of tasks designed to test two kinds of creative thinking: divergent thinking and convergent thinking.
An “alternate uses” task was used to test divergent thinking. During this task, participants were asked to think of different uses for a variety of common household objects. Answers were scored based on originality (compared to the answers other subjects came up with), fluency (the total answers a subject could come up with in the given time), flexibility (the range of ideas) and the details used to elaborate on each idea.
Convergent thinking was evaluated using a “remote associates” task during which the subjects were asked to find a common link between three unrelated words. For this task, there was considered to be one correct answer for each set of words.
High Dose of THC Produces Poorer Results
The researchers observed similar performances from the group that was given the low dose of THC and the group that was given the placebo. The “low” dose of THC consisted of 5.5 milligrams—roughly the equivalent of a single joint. There was very little variation in performance during either the divergent thinking tasks or the convergent thinking tasks between the group that took THC and the group that did not receive a drug dose.
However, the group that received the high dose of THC (22 mg) did not perform as well on the divergent thinking tasks. The fluency scores, flexibility scores and originality scores were all significantly lower among the participants who received 22 mg of THC. Convergent thinking scores did not appear to be affected—the high dose of THC group earned similar scores on these tasks as the other two groups.
Using Marijuana for Creative Inhibition Might Be Counterproductive
These results led the researchers to conclude that marijuana does not boost creativity, and can actually have a negative impact on creativity in high enough doses. While some individuals may be tempted to use marijuana to recover from “writer’s block” or other creative difficulties, they may actually be hurting their creativity.