Many college students regale their friends -- and scare their parents -- with tales of widespread and excessive drinking, smoking and other drug use on campus.

But most students "grossly exaggerate" the extent of alcohol and other drug use on their campuses, reveals a study published in the May issue of the Journal of American College Health.. Even on campuses where most students report abstinence or infrequent use of a variety of drugs in anonymous surveys, the same students substantially overestimate what their peers are doing.

The study utilized 1994-96 data in 48,168 student surveys from 100 institutions nationwide that conducted the Core Alcohol and Drug Survey. Co-directed by Phil Meilman, director of counseling and psychological services and courtesy professor of human development at Cornell, the Core Survey project was developed under a grant from the U.S. Department of Education's Drug Prevention Program in Higher Education. The Core Institute manages the nation's largest database on collegiate alcohol and drug use.

"This study sheds new light on the problem of misperceptions of norms by examining the phenomenon across a wide variety of campuses," Meilman said. "The findings of substantial exaggeration are consistent and robust."

Alcohol use, particularly high-risk or "binge" drinking, is increasingly recognized as a serious problem among college students, and the authors warn that this study should not be used to minimize the problem but to develop better prevention strategies.

The new study showed that many students accept popular images of college culture as displayed in movies like "Animal House," with excessive drinking and drug use, as the norm.

"Although alcohol and other drug related deaths and harm are a tragic concern, widespread coverage by the news media about excessive drinking on campuses adds to the negative image," said H. Wesley Perkins, professor of sociology at Hobart and William Smith Colleges, and lead author on the report.

In spite of the popular image, however, the study found that, on most of the 100 campuses included in the survey, the majority of students reported they did not engage in regular weekly

drinking, use tobacco products or smoke marijuana. At all the schools, only very small percentages reported use of cocaine, amphetamines, sedatives, hallucinogens, opiates, inhalants, designer drugs or steroids.

But no matter what the individual campus utilization patterns looked like, students consistently reported that they perceived a higher use of these substances than actually occurred. For example, on campuses where abstinence from alcohol was the norm, students perceived that the typical student drank every week. On campuses where most students do not smoke, more than three-quarters of students thought that the typical student used tobacco weekly, and almost half the students assumed that the typical student used tobacco every day. Students' perceptions of marijuana use were similar to those for tobacco.

"Thus, inflated misperceptions of the norm for use of various drugs were commonplace," the study's authors write. "For example, the majority of respondents erroneously believed that the 'average student' used cocaine (...the mean percentage of cocaine users on these campuses was 3.0%). Likewise, the majority of students believed that steroid use was the norm among their fellow students, yet no more than 3.4% of students on any campus reported any use of steroids."

"We were struck by the fact that while overestimations were rampant, underestimations of substance use were absent," said Cheryl Presley, executive director of the Core Institute and associate director of student health programs at Southern Illinois University at Carbondale. "In fact, it was very rare to find a student with a deflated perception of alcohol or other drug use," added Jami Leichliter, assistant director of the Core Institute.

The authors attribute the wide gap between reality and perception to "students' myopically constructed impressions of their peers based on limited personal information about each others' habits. Students must rely on impressions of their culture gleaned from behavior that gains the most attention from peers .... Casual conversation then reinforces and amplifies these observations into solid beliefs about what 'everyone' is doing, all further accentuated by mass media and entertainment images provided for college youths and young adults."

The study's findings can be used to develop media campaigns, orientation programs, workshops and other techniques to inform students "that the norm among their peers is far less oriented to drugs than they believe," the authors conclude. "When students more accurately view their peers as less permissive, they become more constrained by this more realistic perception of their peer norm and they are less likely to exhibit problematic use themselves."

Authors of the study are H. Wesley Perkins; Philip W. Meilman; Jami S. Leichliter; Jeffrey R. Cashin, senior research statistician with Nielsen Media Research; and Cheryl A. Presley.