It may be men who are more inclined to want children while childless women are unsure, or firmly against the idea.

When Matt proposed to Emma he stipulated one non-negotiable condition. Children.

Matt wanted kids. Emma, who was in her early thirties at the time, didn't want them and never had. But she loved Matt, so she agreed to his terms, hoping that one day the much-spoken-about 'mum gene' would kick in and she'd be ravenous with baby hunger.

Nine years later, she still hasn't felt that yearning for children — the one where you gladly sacrifice your income, social status and pelvic floor in exchange for a squirming bundle of joy of your very own.

According to popular culture, Emma and Matt are an anomaly. Childless thirty-something women are supposed to be baby-crazed monsters who view men as little more than sperm repositories. And men must be constantly vigilant lest they get 'trapped' by one of those predatory women who prick holes in condoms.

But as Bryce R. Covert writes in New York Magazine, it may be men who are more inclined to want children, while childless women are unsure, or firmly against the idea.

"In a nationally representative survey of single, childless people in 2011, more men than women said they wanted kids," Covert writes. "A different poll from 2013 echoed those findings, with more than 80 per cent of men saying they'd always wanted to be a father or at least thought they would be someday. Just 70 percent of women felt the same."

Jane, a 49 year old Human Resource executive — and childless by choice — has seen this play out in her dating experience.

"It always seems to be the guys who bring it up," Jane tells me in a café that sells as many baby chinos as it does lattes. "Usually around the third date they'll say something about how they want kids one day. I'll tell them that that's not something I'll ever want to do, and then I never hear from them again."

Over the years, friends, concerned relatives and doctors have tried to change Jane's mind. She'll want children when she meets 'the one', they tell her.

"I've met the right guy, I still didn't want to have his kids," she says.

Working in human resources, Jane gets a daily reminder of what having children can do to women's careers.

"It's always the woman who takes the day off work when the kid is sick. It's the mother, not the father, who comes in late and leaves early because of the school run.

"And I've seen plenty of men who have been forced by unemployment to stay home and look after the kids and they hated it. They hated the loss of social status and they couldn't get back into the workforce quick enough. Why would I want that for myself?" Jane asks.

The research is quite clear that while having children can benefit men's careers, in the form of promotions and pay rises, it has the opposite effect on women's careers.

As a 2010 National Centre for Social and Economic Modelling (NATSEM) report confirms, "among full-time wage and salary earners, women with dependent children earn 7.5 per cent less than women without dependent children, whilst men with dependent children have slightly higher earnings than men who do not have dependent children."

And that's if the woman manages to keep her job at all. Despite being illegal, too many women are made redundant while they are pregnant or on maternity leave to believe that it's just a coincidence.

Childless women can no longer believe in the promise of domestic equality. In even the most egalitarian households the burden of childcare and domestic work falls mostly to the woman — even when both parents work outside the home.

The father helps but the mother is ultimately responsible.

Even when the father does assume some domestic responsibilities it is almost always the mother's headspace and emotional energy that is expended on keeping track of vaccinations, making sure there's enough nappies in the house, managing childcare arrangements, arranging birthday parties, extra curricular activities and medical appointments.

It's not just that the men can't be bothered, don't have the time or don't have the skills. Many men still truly believe that it's simply not their job.

In my own friendship network, I've seen men who have presented detailed arguments about equality, only to undergo what seems like a personality change when children arrive. It's like a switch labeled 'Breadwinner' goes on when they get home from hospital. Providing for their partner and children remains so deeply embedded in their identity that not only is it inconceivable that they would become the primary carer, they actually want their educated, ambitious and successful partner to give up her career and stay home.

Jane says that when it comes to childcare responsibilities, the young men she works with have the same attitudes as the older ones.

"They still think that once you're a woman who has kids your job is to take care of them, and they don't understand women who come back to work. I used to think that these attitudes would change with the next generation but I've lost faith that that will happen."

If this is the case — that children can turn egalitarian relationships into a 1950s-esque domestic prison sentence — then it's not surprising that some women are hesitating, if not firmly against the whole idea.

Kasey Edwards is a writer and best-selling author.