Perhaps the simplest explanation for tobacco’s gateway drug function involves what teenagers learn when they smoke cigarettes. According to one source, “. . .the gateway drug phenomenon is simply an example of practice conditioning, that leads to the development of learned behaviour. Children who experiment with and later use gateway drugs are, in effect, practising the wrong social skills and learning the wrong behaviours. They then apply these conditional behaviours to other more sinister functions…” Adolescent cigarette smokers acquire and practice a number of skills that make it easier to use illicit drugs. First, they learn to administer drugs by mastering the complex behaviour of smoking. Marijuana, crack, and to a lesser extent, opiates are introduced into the body through smoking. The veteran adolescent smoker overcomes the body’s initial negative reaction of acute irritation, coughing, and nausea that result when one first inhales smoke. Extensive use by adolescents of low-tar, filtered brands facilitates acquisition of smoking behaviour. The bodies of adolescent smokers adapt or become desensitized so smoking marijuana does not create the initial adverse reaction in a veteran cigarette smoker that a nonsmoker experiences when beginning marijuana use. The veteran smoker also becomes comfortable and familiar with the process of lighting up, handling, holding, inhaling, and exhaling, which are ritualistic learned behaviours that accompany illicit drug use. Veteran adolescent tobacco users also acquire the ability to ‘unit dose” so not too much or too little of the psychoactive drug is administered. Smokers quickly learn to deliver the desired therapeutic dose by adjusting the number of puffs taken, degree of inhalation, and duration of holding smoke in the lungs. Mastery of these nicotine dose regulator skills facilitate the ability to use and get high on other drugs.

Teenagers who smoke cigarettes often do so in violation of parental wishes, school rules, and state laws. This practice fosters development of skills to conceal cigarette use. The behaviour of masking signs of use such as breath odor, denying use and lying to parents or officials also are practiced. These same skills can be useful for a rookie illegal drug user.
Nicotine users learn that moods and feelings can be modulated or altered by using drugs. Cigarette smokers discover that these chemical lifts are immediate and do indeed make one feel better. Conversely, adolescent smokers who learn to cope with boredom and stress by taking chemical shortcuts may be less likely to develop acceptable, healthy coping skills to deal with life’s challenges. Their deficiency of healthy coping skills and their direct experience with nicotine’s stress reduction function predisposes them to behaviour patterns of using other substances for mood altering purposes.