It's a rough road to manhood for young guys, who more than ever are finding themselves confounded and conflicted about what "masculinity" means.
Behavioral researchers say being a heterosexual male used to mean being macho, but guys today get mixed messages on all fronts as they navigate sex, drinking, friendships and the future.
"The social messages ... about how to be a good person or a good guy vary quite widely," says Glenn Good, professor of counseling psychology at the University of Missouri-Columbia.
Joseph Hammer, 23, who is working on a master's in counseling at Missouri, hears a lot of competing messages. "Your parents tell you things. Your friends tell you things. Your teachers tell you things. You see things on TV."
"Guys know they're supposed to treat women as equals," says Andrew Smiler, an assistant professor of psychology at the State University of New York-Oswego. "But we haven't changed masculinity and we haven't taught boys and men how to deal with these women.
"We still tell boys and men they should be in charge and wear the pants," he adds. "Those are two messages -- you want someone who is your equal, and you should still be in charge."
In his 2007 book Boys Adrift, family physician Leonard Sax of Malvern, Pa., suggests that many young men are becoming slackers, in part because of too many hours of video games and a dearth of role models that undermine male motivation.
In the past, images of manhood glorified drinking and womanizing, researchers say, but today, they note, there seems to be equal pressure to be sensitive.
"A large proportion of young males view drinking and having sexual conquests as the appropriate way to begin to prove they are an adult male," Good says. "Their male peers are saying 'Be tough' and girls are saying 'Tell me about your feelings."
Guys pal around and do "guy" things, like play video games, talk sports, watch porn, binge-drink and hook up, which sociologist and gender studies expert Michael Kimmel of Stony Brook University-New York discusses in his new book Guyland. It's based on surveys of 13,000 students at 17 colleges about sexual "hooking up." And he interviewed 400 young men, most in their 20s.
"The middle-class white idea of proving masculinity becomes the dominant form on campuses today. It's more intense and pervasive than ever before," he says.
Kimmel, 57, says there has always been "guy culture," but what's acceptable has changed.
"My generation's 'dating etiquette' is now called sexual assault," he says. "What we used to think was typical office behavior is now sexual harassment."
Kimmel says these hard-partying behaviors are "almost universal" from ages 16 to 26 and are most prevalent on campuses, especially at large public universities. But they are also evident among both minorities on campus and working-class males.
In their early 20s, "around relationships and around careers, women seem more focused and task-oriented and have a better-defined life plan than the men do," Kimmel says. He worries that "that leads men to look more irresponsible or slackerly."
That's not true, he adds: "They just haven't figured out what they have to do to get on track."
Kenny Gillis, a 2005 mechanical engineering graduate from the University of Colorado-Boulder, is finishing a stint in Williamstown, Mass., with a company that leads bicycle tours for teens.