Britney Spears has one. So do Gwyneth Paltrow and Rosie O’Donnell. And the tabloids say actress Elizabeth Hurley is always on the hunt for a good one.

In Hollywood at least, having a male nanny, or a "manny," is all the rage these days.

But this is Washington. And Adam Good can get a little lonely.

On a recent hot summer day, Good climbed into his turquoise Mazda "manny mobile" for a trip to preschool to pick up 4-year-old Abby and 3-year-old Jake. Two car seats were carefully strapped in the back. And instead of the detritus most other 25-year-old males might accumulate in their cars, Good’s was filled with bottles of bubbles, animal cracker crumbs, a big Snow White book and CDs that ran the gamut from David Bowie and French rap to the ABC song.

Just like Britney’s manny — Perry Taylor, a U.S. Naval Academy grad and Easton, Md., native — Good is a live-in manny.
He does the grocery shopping. (He loves Trader Joe’s.) He does laundry. He picks up dry cleaning. He takes digital photos and videos of the kids or writes up funny things they say and e-mails notes to their parents through the day. He sets up play dates and arranges trips to the park and downtown museums. He cooks dinner — what he calls "nouveau kid." And when Abby and Jake want to play dress-up, he plays, too. "I’m usually a pterodactyl," he says.

And just like Britney’s manny, dubbed "Perry Poppins" by the tabloids, Good gets his fair share of startled stares and rude questions. No, he’s not gay. His fiancee is in the Peace Corps in Uganda. And, no, he’s not a girly man. "I love being with kids," he shrugs. "It’s weird to think that not hanging out with kids is considered manly. What does that say about our roles?"

What, indeed?

In fact, Good’s question — and his current career — is fodder not only for countless marital arguments, but also for a fierce academic feud: Just how caring is a man? On one side, scientists who study evolution — many of them men — say that males of all species are biologically predisposed to procreate with multiple partners and have little or nothing to do with any offspring. Other scientists who study evolution — many of them women — argue that gender roles have less to do with biology and more to do with social and political pressures. Humans are adaptable, they say, and gender roles are not rigid.

So Good is either a fluke, according to one theory, or a sign of evolutionary progress, according to the other. Whichever it is, news of Britney’s manny has unearthed a host of others around the globe: the rugby player-manny in South Africa, the graduate of a prestigious English nanny school in London and the "Manny Diaries" of many others. In the media, at least, mannies are the latest hot thing.

But to Good, it’s just a job. And he likes it. "The money’s good," he says. "And not paying rent in D.C., that’s huge."

At the preschool, Jake was racing around, giggling, refusing to put his shoes on. "You’ve got to go potty before we go," Good told him. Jake continued to run in circles. Good squatted down, looked right into Jake’s little eyes and said calmly, "Potty or Pull-Up, what do you think?" Vanquished, Jake trotted off to the toilet rather than being forced to wear the glorified diaper. Once there, his efforts were met with Good’s "Oh my gosh. Good work! Good work!"

Across the hall, Abby rushed up to Good and flung her arms around him. As he lifted her to give her a hug, he and Gary Mayes, one of the few male teachers at the preschool, talked about the previous night’s "graduation." Mayes said Good, as a manny, is a rare bird. But then again, so is he. Nationwide, men make up less than 3 percent of all preschool teachers and 9 percent of all elementary school teachers.

"From a kid’s perspective, it keeps things gender-blind," Mayes said. "In this profession, sadly, you become stereotypically gender-identified. You know, women are nurturing. Men are not nurturing."

That’s at least what David Geary, an evolutionary psychologist at the University of Missouri, might say. "This bias, where you see moms tending to kids, taking greater interest in kids, is found in 95 to 97 percent of the millions of species on Earth. In most species, males don’t do anything in terms of offspring," he said. "Humans are, in fact, pretty unusual in that we have male parenting at all."

Geary doesn’t understand the manny phenomenon.

"I don’t know what’s going on," he said. "I hate to be cynical. I think some of them may actually like it, but, for others, it’s just about making money. It’s not in the nature of many males to do that."

Not so fast, say the scientists on the other side of the debate. Although it’s true that males don’t parent or care about young in 97 percent of the species on Earth, the number is almost as high for females. "It’s misleading to say the vast majority of males don’t care. Well . . . the vast majority of females don’t care, either," said Patricia Gowaty, an evolutionary biologist at the University of Georgia.

Further, Gowaty said, studies have shown that some men whose wives are pregnant develop higher levels of a nurturing hormone called prolactin. The studies prove that males can become biologically conditioned to care, she said.

"I suspect that a lot of what we say about human potential and human patterns associated with gender are nothing more than politics," she said.

Adam Good didn’t plan on being a manny. And he probably won’t be one forever. The truth is, he had recently graduated from American University with a degree in English and was writing experimental poetry and working odd jobs, painting, teaching SAT prep courses and baby-sitting to supplement his income while he figured out where to apply for graduate school. (He plans to study information science.) It was getting old. He saw a posting for a live-in nanny on Craigslist and decided to answer. He had been baby-sitting since high school, starting with his two younger brothers, and was a youth counselor at his family church in North Carolina. He makes a mean grilled cheese sandwich. And he really likes kids.

At first, Laura Dove and Dan Solomon, who live in Alexandria, were taken aback. "But the moment he walked in the door, the kids just loved him. My husband loved him. It was obvious he was the guy for us," said Dove, who sometimes works long hours on Capitol Hill.

When they hired him last August, Dove had just finished decorating the nanny’s bedroom with yellow walls, a pretty floral rug and a white iron bed. Good took it all down. "He put in a brown rug." Good lives in the attic, reading and writing poetry. He works 30 hours a week — leaving plenty of time to hang out with his friends in Washington’s alternative poetry world and see indie bands at the 9:30 club. He has health care benefits, and Dove does his taxes for him. The couple have even paid for cooking classes for manny professional development. So his friends don’t tease him about being a manny. "It’s more like envy," he said.

At the preschool, Good finally loaded Abby and Jake into his manny mobile and put on their favorite music about vowels. When talking about preschool pickups, "I almost always say, ‘One of the other mothers,’ " he laughed. "Sometimes I catch myself. Sometimes I don’t."

As the music played, Jake called out, "Do the silly thing!"

"I’m a little too busy driving this pickle to the grocery store," Good answered.

"Do the silly thing!" Jake said again.

"I can’t. I’m too busy flying this helicopter to the moon."

This exchange, it turns out, is the silly thing.

Dove says it’s an example of how Good not only gets her kids but also "gets in their zone."

Back home, Good put Jake down for a nap and fixed Abby a snack. Lately, Abby has taken to coloring on the faces in the newspaper, asking Good to write "Crazy" on top and then hanging them around the house. Good helped her organize her first art show. But instead of art this afternoon, Abby chose a pile of books and climbed onto Good’s lap. He read to her.

A biological fluke? An evolved, caring male?