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.
His last semester of college, he interviewed with several engineering firms and accepted a job.
That spring, "I called them back and said 'I can't do this right now,' " he says. "I wasn't ready to go into the workforce."
But turning 25 last month made him decide to focus more on his long-term goals, he says.
Peers play a critical role in validating gender identity for young men exploring their masculinity, experts say. And even as this generation has more mixed-gender friendships, guy bonding, largely through shared activities, is important, says Geoffrey Greif, a University of Maryland professor who interviewed 400 men of all ages for Buddy System: Understanding Male Friendships.
Late teens and 20s is one of "two peak times" in life when friends play a key role, he adds.
Greg Glasser, 19, of Columbus, Ohio, says he and his friends are into outdoor activities, from basketball to hiking and swimming.
In the fall, football is "huge," says Glasser, a sophomore at Ohio University in Athens.
"Saturdays and Sundays are just football days," he says. "Guys gather around and throw a football in the yard during the day and go to the game and party."
So, if all this exposure to "guy culture" isn't healthy, as some suggest, what's a guy to do?
Kimmel says staying connected with parents and finding at least one close guy friend will help.
Some manage to stay on track, including 22-year-old Layne Held, a credit analyst at a bank in Birmingham, Ala. He graduated in May with a business degree from the University of Georgia in Athens, where "people went to class and wanted to do well.
"I knew going into college I wanted to have fun and meet people, but I realized I was going there to get an education. I had to get my studies done."