Three decades ago, a team of Norwegian researchers hot-boxed a car — for science.
The study volunteers had never smoked marijuana before, but they all piled into a small car for 30 minutes, joints in-hand. Some smoked while the rest were instructed to breathe normally.
The researchers wanted to investigate the same question recently raised by the onscreen antics of Anderson Cooper 360 reporter Randi Kaye, who spent a week reporting on the legalization of marijuana in Colorado: Can you really get a "contact high" from people getting high around you?
According to the Internet, yes and no. An entire thread on Marijuana.com tells stories of the elusive contact high. One comment claims a girl lied to her probation officer that her friend blew smoke in her face, while another tells about getting stoned from her mom.
Similarly, the researchers' findings, published in the Journal of Forensic Science in 1985, were inconclusive — just as most of the other research has been. The Norwegian study only included ten volunteers, and the smokers were told to inhale as little as possible, leaving plenty to breathe for the non-smoking volunteers.
Under those artificial conditions, the researchers found that only certain participants had levels of active agents like THC high enough to generate mental and physiological changes. But none of the participants actually felt high — a finding that appeared in a similar study in which experienced users were told smoke normally.
In fact, the hot-box experiment sounds like a drag for all involved. "No subject experienced any feeling of euphoria," the researchers noted. And "the discomfort caused by the heavy Cannabis smoke during the exposure period was universal."
Still, a contact high might be possible, a later study in Clinical Pharmacology and Therapeutics found — but only under extreme conditions. The researchers instructed their subjects to sit quietly wearing colored goggles while a machine in the middle of the room "smoked" 16 marijuana cigarettes in one hour.
While the physiological effects of the passive smoke inhalation varied, the subjects did report a high this time. No reaction to placebo cigarettes further corroborated the results.
But the researchers estimated that inhaling passive smoke from 16 joints in one hour had a similar effect to actually smoking just one, and they emphasized that different people can react very differently while inhaling similar amounts.
For clarification on the real-life application, we turned to Cecilia J. Hillard, a professor of pharmacology and the director of the Neuroscience Research Center at the Medical College of Wisconsin, who has studied marijuana extensively.
In her expert opinion, she told Business Insider in an email, "the 'contact high' is purely a psychological phenomenon." The lungs, she explained, are extremely good at trapping the THC in marijuana, "and little residual THC is present in the exhaled air."
In other words, people "may experience runny noses or itchy eyes from the smoke"when others smoke marijuana, but they aren't likely to be hit with enough THC to feel high.
A more recent study, published in 2010 in the Journal of Analytic Toxicology, supported this idea, concluding that passive exposure to marijuana smoke under real-life conditions would only leave "trace amounts" of THC in the blood.
So was Randi Kaye actually high when she couldn't stop giggling during her interview with Anderson Cooper?
After all, she spent an entire day riding around in a car full of smokers, reaching levels of exposure greater than most of the experiments on the effects of passive smoke.
Kaye's high is possible — but not probable. Her demeanor was likely influenced as much by the people she spent time with and a placebo effect as by actual THC.
Most people who think they are experiencing a "contact high" should keep in mind that, as an old study in the Journal of Abnormal Psychology concluded, "social setting and belief interact with smaller doses of marijuana."
In other words: Being around a little bit of smoke probably won't get you high, but when you factor in the placebo effect of that same smoke, you might just end up with a case of the giggles.
SEE ALSO: This CNN Reporter Appeared To Have Enjoyed A Tour Of Colorado's Weed Industry A Little Too Much