My favorite TV show as a kid, “Beverly Hills, 90210,” offers an informative glimpse into just how much of prime-time television’s portrayals of marijuana have changed in only a short period of time. Marijuana was overwhelmingly portrayed in a negative light throughout the teen drama’s 10 years on TV (1990-2000). So much so that cannabis immediately served as the gateway drug to a peripheral character’s heroin overdose death in 1997.

The 21st-century remake of “90210” dealt with marijuana use much differently during its 2008-2013 run, though. In fact, marijuana was downright cool on the reincarnated “90210.” The young/hip/brilliant high school teacher smoked it every day back in college; the parents mistakenly ate pot brownies, with good-natured hijinks naturally ensuing; and young love even blossomed at the medical-marijuana dispensary.

The evolution of marijuana depictions from the old to the new “90210” is a microcosm of the growing normalization of weed on TV. The Atlantic documented these changes in an article aptly titled, “How TV Fell in Love with Marijuana.” But others have decried them. The socially conservative Parents Television Council concluded its 2008 analysis, “Prime Time Goes to Pot,” by lamenting the fact that “prime-time television has joined the growing enthusiasm for portraying marijuana use as harmless and even beneficial”

Television’s new love affair with marijuana, of course, coincides with a remarkable increase in support for legalization over the past 15 years. Recent polls by Gallup, Pew and YouGov found a majority of Americans now favor legal recreational use — up more than 20 percentage points since the late 1990s. Moreover, on Election Day, Oregon, Alaska and Washington, D.C., joined Colorado and Washington state in voting to legalize marijuana for recreational use. This growing support, however, naturally raises the chicken-or-egg question of whether TV is portraying pot more positively because of growing public support or if those benign depictions are liberalizing attitudes about legalization.

Fortunately, data from the General Social Survey (GSS) helps shed some light on that question. This venerable resource routinely asks about television consumption and marijuana legalization in its biennial academic surveys. We can, therefore, determine whether Americans who watch more television are actually driving the trend in support for legal weed. We can also control for a whole host of relevant factors (party, ideology, religiosity, age, race, education, news consumption, etc.) to ensure that watching TV, rather than some other variable, is responsible for our findings.

These results, which are presented in the graph below, suggest that television has in fact helped change public opinion about marijuana:


(Note: These are predictions from a statistical model that also accounts for party identification, ideology, religious service attendance, education, age, gender, race, marital status and newspaper consumption. Source: GSS Cumulative File.)

The large increase in support for legalization over the past decade was concentrated among Americans who watch a lot of TV. After accounting for other variables, support for marijuana legalization has increased by almost 20 percentage points among individuals who watch at least four hours of TV a day (nearly one-third of the population). Meanwhile, opinions remained relatively static among Americans who do not watch much television.

To be sure, these results are still not definitive proof that television is responsible for the growing trend in support for legalization. Some Americans, for example, may have changed their viewing habits because they approve or disapprove of prime time’s portrayal of pot. Prime-time depictions could have also changed to reflect the views of those who watch the most TV. The much more logical explanation for the pattern in the display above, though, is that TV’s new normalization of marijuana helped change public opinion about its prohibition.