In the present times, some set of managers would assume it for ANY woman of childbearing age. And if a woman doesn't have kids, she's assumed to get pregnant and go on maternity leave.
Imagine what would happen if a guy came in and said "I like this job, but my real passion may be art. There is a %50 chance in the next 5 years I am going to leave my job to peruse that." You'd try to avoid hiring them.
Of course, this has terrible consequences in that it effectively discriminates against women in hiring, but simply trying to get hiring managers "not to be sexist' isn't going to fix the problem. You are asking employers (men and women) to weigh their personal ideals ( gender equality) against financial incentives(retaining employees, not paying to).
The point is that not hiring women because they have kids, is stupid, as the same can happen to men as well. Except for the pregnancy time, of course.
Many European countries, have shared leaves between parents.
Sweden does it :)
Would you say that assumptions is completely unfounded? What percentage of women don't have kids?
A more salient question is why there is discrimination on gender in hiring. Is it outright sexism or is it discounting for the fact that a women is far more likely to exit her career to have kids or reduce her hours. The answer radically effect how you fix the problem.
The study in question: http://www.pnas.org/content/109/41/16474.full.pdf
It's not such a huge point if you read the bio at the top of the article and noticed that the author lives in Australia and not just assume he lives in the US.
Mind you, Australia does have similar anti-discrimination laws.
I think you'd be hard pressed to find such a law. What you will more likely find that it is illegal for an employer to discriminate in hiring based on that information, and an employer asking the question in an interview is quite likely to be used in any lawsuit over alleged discrimination as evidence that they were, in fact, discriminating in hiring based on the information, since asking a question in an hiring interview is pretty compelling evidence of an intent to use the response in making hiring decisions.
Some set of hiring managers assumed a mother with kids would likely focus more on family then career. That assumption may or may not be dumb. It's certainly correctable if there is serious statistical evidence it is wrong (unlike someone just being a bigot).
That wouldn't help this case though, because the inclusion of kids in the resume was an intentional signal that mangers were meant to interpret as such. Since the applicants gender was misread, the signal was read as they wanted flexible hours, not that they were stable. Sure, dad's could ask for flexible hours, but that is on the whole a less frequent occurrence.
This is an even stronger single because asking if I have kids in an interview is in fact not legal in most places in the US, so including it your self is making a huge point.
Oh, there's also the fact that if you did interview them and not hire, the fact that it was in their resume might give the grounds for sueing you for gender discrimination.