How did marriage become so unpopular among black Americans? That's the question author Ralph Richard Banks asks in a new book that is generating lots of discussion -- and its share of controversy.

Banks, a law professor at Stanford University, says he came up with the title for his book after reading a 2006 Washington Post article in which a journalist, talking to a group of students about marriage, was told by a 12-year-old boy that marriage was "for white people."

"I was struck by that, because that is the starkest expression one can imagine of the view that marriage has declined so much among African-Americans. That it's not something that black people do; it's only something white people do," Banks told CTV's Canada AM Tuesday.

So Banks decided to turn the boy's statement into a question and investigate how perceptions of marriage are changing among American society.

The book, he says, took over a decade to put together, as he gathered research from a number of different areas, including sociology, psychology, the law, economics, and education.

The final result is a book that answers some provocative questions and opens the discussion about whether society is adjusting to its own changing views on marriage.

"The book was difficult to write because I had to address things that are challenging and that relate to all of our intimate lives. And it sort of implicates everyone," Banks says.

It's no surprise to most of us that fewer people are choosing marriage these days -- not only in America, but throughout most of the Western world. But the drop in marriage rates is most pronounced among African-Americans, a racial group that is leading the shift.

"So what I wanted to do was ask: how we can understand our society better by looking at the experience of African-Americans?" Banks says.

He found that there are essentially two main ways in which the black experience is representative of all of society.

The first is the overall marriage rate decline. There are now more unmarried white women than ever before. Among black women, it's declined the most: almost 70 per cent of black women are unmarried, Banks found.

The other change is in the relationship of husbands and wives. Wives are more likely than ever to earn more, or be better educated, than their husbands, because women have moved ahead educationally and men have fallen behind.

"This trend, as well, is most pronounced among African-Americans, where more than 50 per cent of college-educated black women are married to less-educated or lower-earning men," says Banks.

These changes among the relationships between men and women are also affecting another group: their children. Banks found that more children are being born to unmarried parents.

"This is socially significant," says Banks. "A full 70 per cent of black children are born to unmarried parents in the U.S. This number is higher than it is ever been. And an increasing number of white children are born to unmarried parents," he says.

In the U.S., about 40 per cent of all children are born to unmarried parents, and the percentage rises the younger that the mothers are.

"These are not numbers we should be enthusiastic about, because it is the case that, all things considered, kids do best when they're raised by both parents who are in a loving, functional relationship," says Banks.

In the book, Banks notes that interracial marriage is also on the rise – a development that he sees as positive.

"It's a positive development because it reflects the fact that people can make choices that are best for them," he says.

That's a position that some have taken exception with. In the book, Banks even goes so far as to encourage educated black women to look outside their race to find suitable partners.

Not everyone has accepted Banks' message, with some wondering why women's worth needs to be defined by marriage and others suggesting he is advocating "racial genocide."

Banks says he doesn't mind the controversy, because at least it gets people talking about a topic that many have chosen not to address.

Controversy is good, Banks has been quoted as saying: "A conversation exists where before there was silence."