The American appetite for contentiousness has wasted another opportunity for constructive dialogue.

It happened Friday when radio talk show host William Bennett made a remark involving race and ignited a chorus of explosive reactions. Critics as wide-ranging as the Bush White House and House Democratic leader Nancy Pelosi of California waved their torches, not to shed light but to singe.

Author Deborah Tannen has called this ramparts impulse the “argument culture.” Our default reaction, she contends, is to attack rather than reason, to assign sinister motives rather than explore root causes, to fix blame rather than find solutions.

On Friday Bennett was asked by a caller about a theory that abortion has eliminated millions of workers who might have been employed now, paying into the shaky Social Security trust fund. Bennett wouldn’t go there. Under that kind of thinking, he said, you could rationalize aborting all black babies as a way to reduce crime, a concept he branded “impossible, ridiculous and morally reprehensible.”

That’s where the conversation could have begun, but that’s where it ended.

Away from Bennett’s radio show, the shouting revved up. In a world where decibels count more than logic, he was interpreted as either advocating black infanticide, or branding all blacks as criminals, or both. Bennett responded in kind, denouncing the denouncers. Cable TV panels donned their pads and helmets.

Gone was the opportunity to explore Bennett’s thesis, which might have led to needed “why” and “how” questions.

Why are blacks responsible for a disproportionate amount of crime? Why do minorities remain over-represented in the poverty-stricken populations where there’s too little hope and too much despair? How can a country that calls itself a nation of equal opportunity make the slogan come true?

The fact is, a poor child who grows up in a household where the shelves hold drug paraphernalia instead of books, where cooking ingredients include pseudoephedrine rather than salt and pepper, where education is undervalued and public order is disdained – that child will never have the same opportunity as classmates who enter school clothed, fed and ready to learn and supported by parents who value education and provide positive examples. Race has nothing to do with it, except that the legacy of historic bigotry is too pervasive to be neutralized by a few decades of civil rights legislation.

It’s the same discussion that could have arisen after entertainer Kanye West interpreted the plight of poor blacks in New Orleans as evidence that President Bush doesn’t care about blacks.

In her book, communication specialist Tannen offers a list of suggestions for moving from debate to dialogue. The first recommendation is applicable here: “Don’t demonize those with whom you disagree.”

Until we take that advice seriously, we’ll keep missing opportunities for social advancement.