"When we started the movie it wasn't gonna be mostly women. It was going to be everybody. What we found was that nobody cared about men and their hair. Not even men," said Rock, who has had to go on "Oprah" to defend the movie before suspicious and sometimes hostile female viewers, for whom the subject of artificially straightened or extended hair is a knotty one.

"I wish I didn't have to," said Rock, who got the idea for the movie when his 5-year-old daughter asked him why she didn't have "good" hair. "I want to focus on how funny the movie is, and I think it's the funniest movie I've made."

"Good Hair" is the comedian's take on the complex relationship between black women, their hair and the $9 billion industry that supports that relationship. Rock, the stand-up, is mainly looking for jokes, and steps lightly as he probes what can be freighted with racial and gender anxiety.

Many women have wondered, for example, why women weren't involved in making it. (Rock made it with stand-up pal Jeff Stilson.)

"I didn't stop a woman from making it, and I make fun of no one in this whole thing. This is my little movie that has to do with my daughter's own hair, not a definitive history of hair, which someone could do, and apparently some people want, and probably will be done someday."

Rock gets celebrities (Maya Angelou, Nia Long, the ladies from Salt N Pepa, etc.) to talk about their hairstyles and philosophies, and talks to ordinary folks in barber and beauty shops throughout the country.

What the subjects share is a willingness to be completely candid - Rock said he worked hard to create the atmosphere that made such frankness possible.

"When he was alive, I was good friends with Ed Bradley, and I tried to take that kind of approach to it, just straight down the middle. If you notice, I don't have fancy clothes or makeup; I don't even have my own hair cut. We just really wanted to make people feel at ease," he said.

Rock also goes to India to find the source of the hair used in hair extensions, and visits a hair-industry trade show in Atlanta that turns out to be a bizarre, boisterous slice of Americana.

"Good Hair" makes it clear that Rock takes a dim view of painful procedures for young girls, but he says that's as far as his hair activism goes. Rock denies he's a natural-only hair Nazi, and though he will prevent his own daughters from using relaxers until they're 15, after that, they're free to do what they want.

"Women want to have fun with their hair, I get that. The movie is not pro-relaxant or anti-relaxant, it's not pro-natural. It's just about the whole phenomenon of women and their hair. And the thing you get out of it, hopefully, is that women are just really into beauty, in a way that men are not.

"Women are really into fashion, and hair is a part of that. They notice what other women are doing. A woman will go to work, look at another woman and say, 'Oooh, she's wearing my dress.' No guy goes to work and says, 'Hey, that guy's wearing my pants.' They just don't care," he said.

Women's hair, he said, is tied up in their interest with fashion, he said, and probably doesn't have much to do with men, which is good.

"From what I can tell, hair is just not a deal-breaker for men. There have been all kinds of hairstyles through the years, all kinds of dress styles, and the birthrate has never gone down," Rock observed.

Activist Al Sharpton shows up in "Good Hair" to explain the origin of his straightened strands, but otherwise, men are in the margin.

Rock notes that men tend to establish a preference early in life, then maintain that one style forever, spending billions on Rogaine if they have to.

"When it comes to hair, a man's sense of style comes from whatever style he had when he first [had sex]. They think, wow, this will work? And they stick with it forever."

On the other hand, he said, everybody these days feels extra pressure to look good.

"Celebrity culture has just sort of taken over. When I was growing up, it wasn't the hip thing, wanting to be a star. In those days, you had the reluctant star. They don't exist anymore. Today, everybody wants to be a celebrity, and everybody's camera-ready."

Rock was not so reluctant to star in "Death at a Funeral," due out early next year. It's a U.S. remake of the overlooked British comedy about a man who hosts his father's funeral, where events go horribly wrong, thanks in part to his brother (played this time by Martin Lawrence).