There is no scientific definition of social smokers, though researchers label people who smoke one to five cigarettes daily as 'chippers' to signify they are getting periodic peak levels of nicotine in the body rather than the constant blood level in smokers who partake more frequently.
—Bob Condor, "Even for Social Smokers, Tobacco Takes a Toll," Chicago Tribune, December 8, 1999

At the University of Pittsburgh, for example, Dr. Saul Shiffman, a clinical psychologist, studies chippers — people who are able to smoke just a few cigarettes regularly but never become pack-a-day smokers.

Shiffman, who presented his findings last week at the American Psychological Association annual meeting in New York, estimates that about 4 to 5 percent of the 55 million Americans who smoke are chippers. Unlike the pack-a-day smoker, chippers smoke no more than five cigarettes a day and usually smoke only about four days a week. chippers are not smokers who have tried to quit and slipped back to their old habits but are people who can be satisfied smoking just a few cigarettes on a regular basis. Rather than smoking because they feel pressured, tense or are experiencing withdrawal from nicotine, chippers usually smoke because they are happy or are enjoying themselves, for instance at a party.
—Sally Squires, "Why Can Some People Smoke Without Getting Hooked?," The Washington Post, September 8, 1997