Hazing has been banned by 44 states and virtually all colleges and universities. In fact, half of those who reported experiences that constitute being hazed said they were aware of anti-hazing policies, the study said.

However, nine out of 10 students who reported being subjected to behavior that constitutes hazing didn't believe they had been hazed, the professors said.

Activities the survey counted as hazing were skits or roasts where members are humiliated, singing or chanting in public, wearing embarrassing clothing, being yelled or cursed at, enduring harsh weather without proper clothing, drinking large amounts of alcohol, and watching or engaging in sex acts. As campuses have cracked down on alcohol, pledges or new members also sometimes have been forced to drink large quantities of water or milk, sometimes with deadly results, Allan said.

Gary Powell, a hazing expert in Cincinnati, said defining hazing is a potential problem with any study. Drinking to excess and physical abuse clearly are hazing, but the line is blurry for activities that don’t put people at risk of injury, he said.

Many people define hazing the way Supreme Court Justice Potter Stewart famously defined pornography: “’I know it when I see it,’” said Powell, who dealt with liability issues while working for a law firm that represents fraternities and sororities.

Allan and Madden didn't try to recommend solutions, but Madden said it’s clear there’s plenty of work to be done when a strong majority of students who are hazed don’t realize it.

“They’ll call it something else, team-building, or say ‘I gave my permission to be treated this way.’ It’s a challenge for college administrators,” Pollard said.

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