Why does bad behavior persist in fraternities?

Racist chants. Nude photos of unconscious women. A criminal investigation into hazing. Fraternities, as social groups of male college students are known at American universities, seem to be coming under fire as never before.

Despite a major push to reduce drinking and sexual assault on U.S. campuses and increase diversity, some fraternity chapters have failed to clean up their acts and are embroiled in major scandals. Universities and the fraternities' national offices are quickly punishing the offenders amid more promises of reform.

Fraternities have about 372,000 members among 7.7 million male undergraduate college students in the U.S. Despite their relatively small membership, they and their female counterparts, sororities, have long been the social backbone of many campuses, holding weekend parties and social events.

Members see them as a way to make friends and gain valuable professional connections. And they perform charitable works. At Penn State, for example, the Greek system raises millions of dollars each year for children with cancer.

Bad behavior inside the walls of a frat house — or on campus generally — is nothing new, of course. Alcohol, immaturity and freedom from parents have been a potentially troublesome combination for generations of American college students.

But incidents at the University of Oklahoma and Penn State, in particular, have stunned many and happened despite heavy scrutiny of misconduct at colleges. Some of the behavior has been so bad that it would shock the frat boys of "Animal House," the classic comedy about a group of outcasts that starred the late John Belushi.

Some critics blame popular culture, saying it's making fraternities essentially ungovernable.

"There's this underlying acceptance that boys will be boys, this is fraternity life and this is what you have to accept when you walk through the doors of a fraternity," Ellen Kramer, legal director of the Pennsylvania Coalition Against Domestic Violence, said Wednesday.

At Penn State, police are investigating allegations members of Kappa Delta Rho used a private Facebook page to post photos of nude and partly nude women, some apparently asleep or passed out. A former member told police the invitation-only page was used to share photos of "unsuspecting victims, drug sales and hazing," according to court documents.

The Facebook posts were "very sad and very offensive," Penn State President Eric Barron said Wednesday, adding that students could be expelled. Referring to Penn State's fraternity system, Barron added: "It's just unfortunately a large system with some very fine young men and some men who are not doing smart things."

The page came to light Monday, nearly a week after a University of Oklahoma fraternity was shut down when members were caught on video singing a racist song. The university expelled two students identified as ringleaders. Sigma Alpha Epsilon disbanded its Oklahoma chapter and announced Wednesday it will require all its members nationwide to go through diversity training.

"We are focused on trying to determine the root of this song or this chant, where it came from, that's our primary focus," said Blaine Ayers, executive director of SAE, adding he was disgusted and embarrassed by the video.

Why do the problems persist?

"That's a legitimate question," said Peter Smithhisler, president of the North-American Interfraternity Conference. "My response is that when fraternities are made aware of behaviors inconsistent with their policies or values, they are swift to action, and individual chapters are held accountable when appropriate."

Smithhisler's group has created three commissions to study hazing, drinking and sexual assault and come up with recommendations for fraternities. The study groups have yet to complete their work.

Some colleges have gone to extremes to address the problems. Colby and Bowdoin colleges in Maine banned fraternities in the 1980s and '90s. Dartmouth College in New Hampshire, which helped inspire "Animal House," recently banned hard liquor and is overhauling its housing system.

Allison Tombros Korman, executive director of Culture of Respect, a group formed in October to prevent sexual assaults, said fraternities and universities can drastically reduce problems by targeting campus "social influencers" — fraternity presidents, athletes and other campus leaders — who set the tone for their organizations.

"I don't think it's an impossible task at all. I don't want to sell young people short," she said. "I think they are capable of making good choices and moving away from these types of behaviors."