The Hollywood hero races his convertible down the boulevard for a date he can’t miss. It might be with a lover or a terrorist or a CIA officer, but it probably won’t involve a cigarette. A new study finds that in studio films, the most likely people to be lighting up are lower-class male villains.

Karan Omidvari, a pulmonary physician at St. Michael’s Medical Center in Newark, N.J., and his colleagues watched 447 movies released after 1990 to quantify exactly who smokes on screen—an intentional scripted act. Omidvari found that the seven big companies, such as Paramount and Universal, that make up the Hollywood studio system do have a plan: villains smoked nearly twice as often as heroes; men more than women; and poor characters more than rich ones.

Why this profile exists is difficult to say, however. In movies from the 1950s and 1960s, many glamorous leading men and women smoked. Modern Hollywood films may just be reflecting U.S. population statistics, which show that lower-income people smoke more. Omidvari does not think Hollywood is shilling for tobacco companies. He concedes that villainous characters are often popular with teenagers but maintains that it is hard to say if the propensity of such characters to smoke represents a deliberate effort to get teenagers to pick up the habit.

Interestingly, Omidvari found that independently produced R-rated films are more likely to glorify smoking—51 percent of the characters smoked, compared with 31 percent in Hollywood’s R movies. If there is an attempt to influence smoking habits, “it is being orchestrated by independent movies,” Omidvari says. He speculates that independent filmmakers might have more trouble raising money, and so some may accept product-placement financing.