The effects of the "feminization" of the American male is something I must deal with everyday.
I think in general boys are happier and more motivated if they have one or more adult male parents or relatives closely involved in their lives. And I think women, deaf people, white people, black people, and just about any other distinct group benefit from having one or more "same type" role models handy on a long term basis. But the absence of a father is the least of the problems of these (mostly black) kids who are completely out of control in public middle schools and high schools. Their relatives are usually all very uneducated, have irregular and very low-level low-responsibility jobs (if they're not just permanently on welfare), and are in many cases using drugs and alcohol heavily. There are no limits whatsoever on TV, junk food, where the kids go, be home by X time, etc. Their technical fathers are usually the sort of people who'd be nothing but a bad influence if they were living in the home with the kids -- they're gang members, drug dealers, petty criminals, etc. And by high school, many of these boys are already technical fathers themselves.
Dig up the research on children raised by early-widowed mothers. They have no fathers, and yet they in no way resemble the animal-like creatures that are causing complete chaos in inner-city schools. The boys may wish they had a dad, but they nonetheless refrain from mayhem, graduate from high school, go to college if their parents went to college, get decent jobs and support themselves as adults, at the same rate that boys raised in 2 parent homes do.