“Dear Abby” Statistics, Awash in Ignorance and Presented Ass-Backwards

Last week the Editorial Board of the Wall Street Journal published an opinion piece that has Harry Anslinger grinning in his grave. They included the oft-cited statistic so old it has whiskers: 95% of heroin users began by smoking marijuana. This is a textbook example of fearmongering, the term for deliberately spreading frightening rumors to sway public opinion. 

The long-ago discredited gateway theory was built on that single misleading statistic and concludes marijuana use unfailingly leads to heroin addiction. The premise is that people who use mood-altering substances progress through a linear sequence of stages beginning with socially and legally acceptable psychotropics (caffeine, alcohol and nicotine), then cannabis, then heroin. Following that rationale, it is easy to see most heroin users can be said to have begun their addictions by using caffeine, alcohol, and nicotine, making them gateway drugs, too. Few call for the banning of caffeine or nicotine, but 100 years ago the United States banned the drinking of alcohol. As most people know, one of the unintended consequences of Prohibition (1920-1933) was the growth of organized crime. Most people do not know, however, the other unintended consequence was the passing of a law that made cannabis illegal.

Proselytizers are those who attempt to convert others to their way of thinking and willing to spread misinformation to achieve their ends, none more so than Harry Anslinger, head of the Bureau of Prohibition.

Seeing the upcoming repeal of the 18th Amendment and knowing his vast bureaucracy would no longer be necessary, Harry got himself appointed as the first commissioner of the Federal Bureau of Narcotics. Needing a new demon to pursue, he chose cannabis because it was used mostly by minorities and jazz musicians, two groups unlike to put up much of a fuss. After getting some how-to advice from famed yellow journalist William Randolph Hearst, Anslinger embarked on a fearmongering campaign. With such notorious propaganda films as Reefer Madness, now a cult classic, Anslinger shrieked that “marihuana is the most violent drug in the history of mankind” and blamed it for causing insanity, sex crimes, and murder. A diehard racist, Harry also claimed it made what he called the “degenerate races” (blacks, Hispanics, and Filipinos) “forget their place in society and think they’re as good as white men.​”

Axe-grinders are those who have strong opinions based upon ulterior motives. Take Parents Opposed to Pot, for example, a well-meaning organization whose philosophy is clearly stated in their name. According to their website, the gateway hypothesis cannot be denied because the math demonstrates a connection between marijuana use and heroin use. Yes, of course there is, just as there is an even higher correlation between heroin use and the use of soft drinks, potatoes, candy bars, and most ingestibles. A wonderful example of unintended irony, their site has an entire section devoted to what they call the lies and propaganda promulgated by those who don’t see things their way.

For the gateway drug hypothesis to hold any water, cannabis use must lead to heroin use more often than not, so let’s do some simple division and see for ourselves. Readily available data indicate about 25 million U.S. adults smoke marijuana and about 1 million are heroin users. This means only about 4% of marijuana users use heroin, which completely contradicts the marijuana-as-gateway-to-heroin argument. Statisticians know if you want to determine cause-and-effect, you put the cause (the independent variable) first and the effect (the dependent variable) second. When you do this, you see that 96% of cannabis users do not use heroin.

After all these years, one woefully misunderstood statistic remains all the evidence statistical illiterates believe they need to conclude causality, including the Editorial Board of the Wall Street Journal. The crucial takeaway for executives is this – the gatekeepers in your organization know so little about what constitutes correlation and causation that they draw upside-down and ass-backward conclusions just like this – and you are unaware they’re doing it. 

Here’s a favorite real-life Dear Abby example of the ludicrousness of selling correlation as causality from an article I wrote two years, ago, Marriage Causes Divorce:

A friend bought a motorcycle. His mother had read most motorcycle accidents occurred during the first six months of ownership. Unaware that those accidents were not related to the calendar (correlation), but to the new rider’s inexperience (causation), her advice to him was to put it in the garage and not ride it for six months.

David helps decision-makers rid their organizations of wrongheaded information. His weekly blog https://www.letstakeacloserlook.com/ is occasionally amusing or interesting. So are his books.