In “One and Only: The Freedom of Having an Only Child and the Joy of Being One” (Simon & Schuster), journalist Lauren Sandler sets out to disprove the negative stereotypes about only children and makes the case that stopping at one lets parents balance the joys of childrearing with the pleasures of a challenging, fulfilling adult life.

“One and Only” has been a great solace to mothers of only children (this writer included). As Sandler shows, fertility rates have broader implications for Judaism. The Jewish Week caught up with Sandler by phone last week. This is an edited version of that conversation:

Q: Did you write this book because you felt stigmatized growing up as an only child?

A: I didn’t grow up with this tarnished image; I really started seeing it as an adult. Parents would say, “We feel like we’ll be terrible people if we don’t give our child a sibling.” I thought if people don’t want another child, why do we do this to ourselves? I wrote this book to pose that question. It’s a topic fraught with emotion and judgment and misinformation.

What are the main myths about only children you want to dispel?

There are hundreds of studies done over the past 100 years that disprove the idea the only children are lonely, selfish and maladjusted. Only children are no different than anyone else except that they tend to be high achievers, have better self-esteem and do better on intelligence tests.

Why does this negative image persist?

One reason is evolutionary biology. We needed to have large numbers of us to evolve as a species. When we were farmers, children were our insurance policy and labor force. But since the Industrial Revolution, that story doesn’t really hold. I think also, we haven’t come to terms with real freedom and agency for women. The more that women are mothers, the less they can be other things. I also think that having kids is a lot of work, so people tell themselves they’re doing it for a reason.

What’s the connection between only children and the future of Judaism?

There is a correlation between religiosity and fertility. The more Orthodox among us tend to have the largest families. The idea of choosing to have one child is a very secular concept. I was raised as a secular feminist in a liberal Jewish tradition that I value and want to pass down. I live in Williamsburg. If I go 10 blocks south, I see people in the same-size apartment raising 12 kids. We secular Jews are not replicating ourselves, whereas the very religious are replicating themselves five- or 10-fold.

Short term, this is relevant in terms of funding, religious affiliation, influence and politics. Long term, if people within the Reform and even Conservative communities keep having smaller families, we’ll end up with an enormous Orthodox population and a tiny, consequently powerless less-observant population. We see this in Israel already. The secular have three or four kids; the ultra-Orthodox have eight to 14. Power in the future will be redrawn by fertility.

Doesn’t that make you, as a secular Jew, want to have more kids?

There are plenty of people who say, “I’d never have another child because I care about global warming.” But I don’t believe that’s actually how we make personal decisions. Having a child is the most personal, intimate and heart-led thing you can do. Unless you have the power of a religious community that defines you, it’s very hard to make an argument about your own personal fertility as it relates to the future of the world. My choice scares me in terms of the future. Those values that allow me to feel comfortable having one child are the exact ones that get threatened by that choice..

Are you worried the secular Judaism will be out-birthed as a result of people choosing smaller families?

We need to start by talking about what this choice means. That’s not an answer, but it’s a start. Maybe we could organize around family policy, so people wouldn’t be deterred from having more kids by the difficulty of reconciling work and parenthood. The United States is in the bottom tier of family policy in the entire world. What it took in Europe, in part, to [build public support for] state-sponsored child care and paid parental leave was anxiety that Europe was dying out, that people were not replacing themselves. There’s been a long history of organizing around progressive policy in the American Jewish tradition. This would be a great place to direct some of that energy right now.