In the wake of the murders of three black teens in Newark and the shooting death of Oakland newspaperman Chauncey Bailey, the nation is in one of its occasional moments of wondering why young inner city men have become so casual about killing one another.

It’s not an easy question. Why wasn’t this kind of behavior common coin in 1950? Or even 1975? Why now?

My two cents: it’s no use blaming mothers. Judith Rich Harris wrote a fine book some years ago, “The Nurture Assumption,” that showed that children are affected more by their peers than their parents. This is starkly clear, for example, in how immigrant kids talk like Americans rather than aping the accents of their parents. How, really, do we expect the typical mother to keep her boy from socializing with his peers, and especially when often said peers beat you up regularly if you refrain from their company?

It’s no use blaming “the black community” either. That term is something of a slogan. Glenn Loury writes, “hundreds of thousands of people mired in a dead end. It is not a community. It does not have an articulated social structure of middle-class and upper-class people and educated workers and carpenters and all the rest living together in harmony.”

It’s no use piping up that America itself is a violent country and referring to the Wild West or Irish neighborhoods a hundred years ago. This is like watching the Mississippi River bridge collapse in Minneapolis and tugging on sleeves reminding people that a water main blew up in New York two weeks before, to make sure people don’t stereotype bridge inspectors.

Clearly, there is an especially violent subculture that has taken root in inner cities, which demands more attention than the more utopian goal of changing the nature of America, or, really, what would appear from the nightly news to be the nature of the human species.

Finally, it’s no use claiming there is no employment available to these guys. Even a cursory study of that issue reveals the sad fact that the problem is that too many men do not seek available jobs, including ones beyond “chump change” (suggested reading: Alford Young, Lawrence Mead). Too often they sell drugs, which has a way of entailing killing people.

I would suggest that the real problem starts with the fact that the men in question tend to have been raised without fathers. These are the first black men to embrace violence this wanton in such numbers — and also the first who grew up in neighborhoods where having a father was unusual.

What created that was when welfare programs were altered in such a way that discouraged poor people from marrying, and made it so that a man could elect not to rear his kids and know that the government would feed them open-endedly. This kind of welfare did not exist until the late sixties.

The first generation raised in the environment that resulted came of age in the early eighties, and big surprise, that’s when this brand of violence begins.

It is also a cruel irony that crack was invented at this very time. To a generation of men raised where working was optional and few grew up watching fathers work at all, selling drugs instead of getting a real job seemed less abnormal than it would have otherwise.

From there, the rest is easy. In maintaining turf and pecking order, what qualifies as the height of brutality at one point soon seems ordinary, and one has to go further to make an impression. Soon, even that’s not far enough. To show you’re fierce in 1975 you stab somebody. In 1985 you shoot somebody. By 1995 that’s so old hat that to show you’re the real deal, you shoot a stranger.

One thing that would help, obviously, is increased gun control. Despite the earnest indignation of the burgherly citizen who wants to bear arms, there have always been times when America has nudged aside general principle for the larger good. One might think of farm subsidies, as originally conceived.

Another would be a cessation of the War on Drugs. No, not just reducing sentences. We need to eliminate altogether the economic incentive not to seek legal work. However, Kurt Schmoke couldn’t get this by in Baltimore when he was mayor there years back, and maybe this isn’t the moment to realistically expect the demise of the Second Prohibition.

The final thing, however, both relevant and doable, is something Cory Booker has already promised: effective prisoner re-entry programs. Prisoners who land on their feet when they come home can be useful as something most of these misled hoodlums never had, Dads.

But we can ease up on Moms, black people, the economy, and America. In relation to the problem at hand, none of those things can be changed. The problem is rooted in complexity and contingency, and will require solutions that recognize and work with that. Neither mudslinging nor utopian fantasies about a perfect economy or a perfect America help the lost people I presume we are concerned about.

Mr. McWhorter is a senior fellow at the Manhattan Institute.