There’s a new book out called The Mommy Brain,” I was telling a friend of mine, a divorced father of two. “It’s about how motherhood makes women smarter.” “So,” he said, “it’s fiction.”

No, wise guy. It’s a thoroughly researched examination of what women learn from parenthood and how it applies to the rest of their lives. And it’s written by a very brainy mom, Katherine Ellison.

Ellison grew up in San Mateo, the youngest of four intellectual snobs who ridiculed their mother for years for doing the “mindless” work of preparing them to happily conquer the world. Two of the kids grew up to be psychiatrists, one became an ear, nose and throat specialist like Dad, and Ellison became a Pulitzer Prize-winning investigative journalist. It was only after becoming a mother herself that Ellison realized the skill, creativity and, yes, brains her mom had to use to rear her children so successfully. The book, published last month, is dedicated to her.

Ellison won her Pulitzer while she was at the San Jose Mercury News, for a series she and two others wrote exposing the scandalous dealings of Ferdinand and Imelda Marcos. That work led to her first book, Imelda: Steel Butterfly of the Philippines. She spent 12 years heading news bureaus in Latin America, first for the Mercury News in Mexico, then in South America for the Miami Herald and Knight Ridder.

In 1990, she married Jack Epstein, who is now deputy foreign editor at the San Francisco Chronicle. They spent the early years of their marriage in Rio, where their two sons were born. As a mother, Ellison started thinking more about the health of the planet that her children would inherit. She quit her job when the boys were toddlers and the family moved to Palo Alto while Ellison studied environmental policy at Stanford University. There she met biologist Gretchen Daily and the two teamed up to write The New Economy of Nature: The Quest to Make Conservation Profitable. For the last five years, Ellison has been living in San Anselmo, freelancing and working on The Mommy Brain.

In the weeks leading up to Mother’s Day, Ellison found herself suddenly in great demand on the talk circuit. She showed up at my house one morning in early May, bubbling with excitement—she’d just gotten a call from the Today show, asking her to make a guest appearance in three days.

Ellison is a fast-talking bundle of energy with a thick mop of wavy brown hair. She has a habit, when concentrating, of placing an index finger on the tip of her nose and pushing it up. She drove up in her Prius and burst in, holding a takeout latte, abuzz over the juggling act she’d have to pull off to prepare for her trip. It’s the kind of multitasking at which mothers, she contends in her book, learn to excel. But she didn’t always give mothers that much credit.

I understand you had some concerns about what motherhood was going to do to your brain.
Definitely. That’s why I put it off until I was nearly 38.

You really thought it was going to make you dumb?
Yes! That was my main concern, probably. I was very, very excited about what I was doing in Latin America as a foreign correspondent, and I had wanted to do this work since I was 13 years old. So the thought that I would have to trade in the “life of the mind” for a nurturing life was worrisome to me.

Was that your observation, looking at other moms?
Well, a “mommy brain,” as we use the phrase today, means an impaired brain, a brain responsible for having just said something stupid, so you get this message all the time that a “mommy brain” is a lesser brain. Also, I remember my sister, who’s a distinguished psychiatrist, saying she definitely felt mentally challenged when she had her kids. And I had the example of my mother. We used to make fun of her for not understanding things in our homework. We called her “the geisha” and felt that what she was doing was subservient and not very intellectual. I came of age in the late ’60s and early ’70s, when we were hearing from feminists like Betty Friedan who said mothers were like “walking corpses” who “operated at the lower level of food and things.” My mother had been so dedicated a nurturer. It was clear that she was not going to do anything else but take care of us and my father while we were young. That was a scary image for me. I didn’t want to be a geisha or a slave.

How did your mom react to being called a geisha? It sounds so cruel!
My mother endured a lot of abuse without complaining, which is why we also called her “the martyr.” We were, I see as I look back, pretty terrible in some ways: four smarty-pants kids who ended up being very high-achievers. My mom, who is really a main inspiration for this book, just quietly poured her own powerful smarts into getting us educated and more or less civilized. Of course, it’s also true that being a mother these days can be a much more cerebrally challenging job. We have to prepare our kids to compete in a much more challenging global economy, while also processing a hugely increased amount of information about supposed or real threats to our children. We have to worry about reportedly increased rates of asthma, autism, ADD and obesity, as well as trans fats, genetically modified foods, mercury in childhood vaccines. We have to be information analysts.

Certainly the need is there, the challenge is there, but a lot of moms don’t rise to it.
Right. Many moms don’t rise to it. They can’t, in some cases because they’re working so hard just to survive, or they won’t—but the extra motivation to do so is powerful. The survival instinct in mammals is so strong that it appears to be a factor in what scientists have found to be an increase in learning and memory capacity in new mothers. Think of it: At no time in your life do you have to learn so much, so fast, with such high stakes. This can all be a very creative intellectual force. And your brain is being concretely changed in the process. I had my children in the ’90s, when the media was full of articles about how you had to stimulate your baby’s growing brain. I was trying everything I’d read about—like having my son Joey, as an infant, sniff vanilla, which was supposed to awaken his senses somehow. I’m sure I went a bit overboard. Yet in the process I realized that I was being exposed to all these avenues of learning that I wouldn’t have been exposed to if I hadn’t been trying to nurture this other human being.

Tell me about oxytocin and how it affects mothers.
I found this to be one of the most intriguing parts of this project. Research on oxytocin has just taken off in the last six or seven years, so people are coming up with new findings about it all the time. It’s a hormone that’s important in labor and breast-feeding, but it’s not just a maternal hormone. It’s a neurotransmitter that apparently affects behavior in both males and females and it’s been linked to the ability to learn in lab animals. Scientists are finding evidence that whenever you establish a relationship of trust, your oxytocin goes up. When you see someone you’ve had good relations with, you get oxytocin. There are studies that show that when women are breast-feeding, they get a huge dose of oxytocin, at the same time their blood pressure goes down, and they become more serene. One of the world’s leading authorities on oxytocin, a Swedish expert named Kerstin Uvnas-Moberg, is convinced—although this hasn’t yet been proven—that, once you get that strong dose of oxytocin, through labor and breast-feeding, you might actually be more susceptible to it because the receptors for oxytocin are changed in the mother’s brain.

Give me some examples of how brain changes from motherhood affect your behavior with the rest of the world.
There’s research that shows that mother rats become more efficient, with increased learning and memory skills. And while human mothers haven’t been studied in labs, many say they experience the same thing.

I interviewed the fire chief in San Francisco, Joanne Hayes-White—the first woman and first mother to be fire chief of any big city department—and she told me that she found that the skills she was using at home—triage, time management, negotiating with her three children—were easily carried over. Working under pressure, handling interruptions, flexibility—all those skills are refined, through much practice, in motherhood.

I don’t think anybody would argue with the idea that parenthood can enhance skills like time management and flexibility. But does that really mean you’re smarter? These may be wonderful qualities, but they’re not going to help you on an IQ test.

So what is smart? Is your definition of “smart” doing well on an IQ test?
When you look at it closely, we don’t seem to have a very clear definition of smart. For instance, there has been a lot of relatively recent focus on “emotional intelligence,” what we used to call “people skills,” and how that can be such a strong factor in good marriages and working relationships, the things that ultimately make you happy. I ended up dividing the core of my book into five chapters, looking at various kinds of intelligence—perceptivity, efficiency, resilience, motivation and emotional intelligence—and showing what the most cutting-edge research says about how they may be changed. And I opened the book with Webster’s definition of “smart”: basically mentally alert, bright. Focused, in other words. As one psychiatrist told me, a mission can do that. Children are a mission and a mission focuses the mind.

Isn’t there a flip side, though? Your ability to focus on something is enhanced, but the thing a parent chooses to focus on is their kid—which, in the workplace, for example, is often a problem.
There is an image that mothers are less dependable because they’re so focused on their kid. But I talked to the person who does the hiring at a big hotel company in Novato and asked what her experience was with working moms. And she said, “I would hire them first any time because they’re more dependable. They need that paycheck and they need the benefits. The others can come and go.” In our society now, a mother is usually both a nurturer and a financial provider. So to be focused on your child also means being focused on your work. When this doesn’t happen, it’s usually because you’re not sure your child is safe. If you have bad daycare, and a lot of mothers do, you’ll be anxious and perhaps not as focused. I use an example in the book of a company in Silicon Valley that has on-site daycare, and they say their working mothers are tremendous assets, motivated and productive. Also, the high-achieving mothers I’ve talked to who felt most blessed by having a “mommy brain” had extraordinary support at home. Hayes-White, for example, has a stay-at-home husband and parents living close by. So she does a lot of mothering, but when she’s at her job, she can focus more sharply on that. In my own case, even though I’m more of the part-time, stay-at-home parent, I’ve got terrific support from my husband, Jack Epstein, who’s a foreign editor at the San Francisco Chronicle and a very devoted, wise dad. If we had more affordable and high-quality childcare and more flexible jobs, like most other industrialized nations, more women would be able to work at their best as well as mother at their best.

When you became a mother, you were already a very motivated career woman, often traveling to dangerous places. How did having kids affect your work life?
They affected it dramatically. For one thing, I took my babies with me on assignment for a year or so each, while they were breast-feeding. I lived in Rio but had responsibility for half a dozen other countries in southern South America, so my babies got schlepped along to reporting in Argentina, Paraguay, Chile, Uruguay, even the Amazon forest. Naturally, in doing so, I was inclined to cut back on the more risky travel. I confess I fought against going to cover a hostage crisis in Peru when there were bombs going off in the streets—and Peru technically wasn’t part of my beat. In that case, I ended up weaning Joey and going alone, because the reporter who’d been covering the story needed a break. To an extent, I think I was working even harder than I had been, to prove there was no question that having a child would make me less capable or motivated. At the same time, I was profoundly grateful to my bosses then, at the Miami Herald, who were so supportive they actually paid for our nanny to travel with me while the babies were breast-feeding. I was their first foreign correspondent who was also a mother, so we were all innovating.

Your three siblings all became doctors, like your dad. When did you decide that wasn’t the path for you?
The truth is, I didn’t really like blood. But when I was 10, I wrote a little essay about our miniature schnauzer, and it got published in Archie comics, and that really got me addicted to writing. They sent me five dollars.

That must have been exciting!
Yeah, I think that’s what did it. And then I went to Nicaragua when I was 16 on the Amigos de las Americas program, vaccinating rural folk against polio and measles, and that’s when I decided I wanted to be a foreign correspondent. I already knew I wanted to be a journalist. But seeing the poverty and the terrible government there were so shocking to me that I thought if others knew, it would make a difference. So I got very ambitious at that point.

How did you get started in journalism?
I did an internship at the Washington Post, so I was in Washington covering the State Department in 1979. Then I went to Cuba that summer and freelanced for the Sacramento Bee and the Miami Herald. Then I worked for Newsweek in London and went to Pakistan and freelanced there. Then I came back and went to work for the San Jose Mercury, covering local news.

What a comedown!
[laughs] I wanted to work from the ground up and it was great that I did that because it was really rigorous training. But I didn’t know if they were ever going to take me seriously. This was during the time of the wars in Nicaragua and El Salvador and Guatemala—so I started going to Central America on my vacations and I’d write stories on spec as a freelancer. Because they were never going to send me. I was covering courts and cops in Palo Alto!

So you started getting meatier assignments at the San Jose Mercury News and won the Pulitzer for your series on the Marcoses.
I was lucky to work on this series with an amazing colleague and investigative reporter, Pete Carey, who is still at the Mercury, and Lew Simons, who has since gone on to work at National Geographic. We got six months to investigate charges that the Marcoses were looting the Philippines’ treasury, partly in order to buy real estate in the U.S. Based on our series, the Assembly in the Philippines declared that there should be an investigation of the so-called hidden wealth. There were endless stories from that, and I was sent many times to cover breaking news in the Philippines. After we got the Pulitzer, my editors finally agreed to send me to their Mexico City bureau as the bureau chief.

And you had some adventures there. Tell me about the time you were abducted.
I used to travel everywhere with this wonderful friend who’s a photographer. She and I were covering a land reform dispute. And we somehow got cast as the “intellectual authors” of this takeover by squatters. It was two groups of campesinos—peasants—fighting over the same piece of land. And the people who were challenging the squatters came and surrounded us with knives. They were in cahoots with city hall. So they took us at knifepoint to a jail cell. They let us go after six hours. In retrospect, it was really funny.

It was?
Yeah, there was something comical about it. Like my friend pretended she was crying—she’s got this blond hair and a really angelic face—and some of them started feeling sorry for her. We were both so astounded that it was happening that we weren’t that scared. Until afterwards—then we started getting scared.

After five years in Mexico, you were bureau chief in South America for the Miami Herald. What kinds of stories did you cover there?
I covered everything from Avon ladies in the Amazon to the rise and fall of interest rates to hunting down Nazi refugees to World Cup soccer matches. But eventually, I had a serious disagreement with my bosses, after Knight Ridder Newspapers took over the Herald’s control of the bureau. I felt that our keenest interest, as Americans, should be in the environment that we all share—and that was the main story. They wanted me to do more pieces on samba and soccer. And I was willing to do some of them, but I really wanted to do more environmental work.

What prompted your interest?
I think it was partly because of the kids. I had two sons by then. If you know that part of you is going to be living in a degraded environment, it makes it a lot more immediate. I’m very concerned about climate change, in particular, and appalled at how primitively our government is responding to this threat. You know, the rest of the world is catching on so much quicker. In Brazil, in the ’90s, climate change was much more in the news, and there was no illusion, as there unfortunately is in the U.S., that it’s a matter of scientific debate. Also, going to the Amazon and seeing the destruction really hit home for me. We live in such a bubble here.

You wrote a book about environmental economics, The New Economy of Nature: The Quest to Make Conservation Profitable.
In 1999, I left Rio and went to Stanford University to study environmental policy on a John S. Knight Fellowship, which is a program that pays for mid-career journalists to basically do whatever they want for a glorious nine months. By then, my kids were 4 and 1 years old, and I was also realizing I needed a more flexible schedule and one in which I didn’t have to travel so much. In one of my lectures, I met Professor Gretchen Daily, a biologist who works closely with Paul Ehrlich. And she suggested that we write this book. There’s a movement all over the world, in which entrepreneurs are pioneering projects to show that even though environmental “services”—for instance, water-filtration by watersheds, such as Mt. Tam, or pollination by native bees—aren’t included in the GNP, there are ways to capture their value with a little imaginative accounting. I just wrote a story, for instance, about a program in Mexico in which the government has started to pay small farmers living in a biological reserve to be stewards of the forest—to not cut trees and to alert officials if they see the land degraded—because that forest is important for water services for several thousand people downstream.

What else are you working on?
I’ve got a couple of projects lined up for this year. I’m hoping to go to Venezuela later this summer to do a magazine story on the presidency of Hugo Chavez. And I’m working with a good friend and very smart environmental lawyer in Fairfax, David Weinsoff, on a project he designed to put out a handbook explaining environmental law for activists. I’m also doing a monthly column for the journal of the Ecological Society of America. And tomorrow I’m flying to New York to do the Today show. But this afternoon, I have to get my older son to swim practice.