Women with kids are more than a third less likely to get a job interview than an identical CV from a man, scientists reveal.
And even without children, they are still nearly a quarter less likely to even get a call back.
In fact the only women who had an equal chance to men were experienced, well-qualified and childless.
Overall, the study found that women are on average 30% less likely to be called for a job interview than men with the same CV.
Researchers from the Department of Political and Social Sciences at the University Pompeu Fabra in Barcelona sent 5,600 identical male and female CVs for 1,372 real job offers in Barcelona and Madrid.
These covered an age range of 37-39 in 18 different occupations with varying degrees of qualification and responsibilities that were required.
Overall, the likelihood of receiving a call to a job interview was 30% lower for women than for men.
The study, presented at CaixaForum in Madrid, reveals that the likelihood of receiving a call for an interview was 23.5% lower for women without children than for men in identical circumstances.
But once women had children, their likelihood of an interview fell sharply to 35.9 % less than men with kids.
Author and associate professor at the Department of Political and Social Sciences at UPF, Clara Cortina, said: "Women with children suffer increased discrimination in job recruitment processes, as they face a double penalty: womanhood plus motherhood.
"Mothers are on average less likely to be called for a job interview than fathers.
"Despite the gender differences, discrimination against women persists, but to a lesser extent, when candidates are better prepared for the position than the post requires.
"That is, gender penalisation is lesser if, in addition to what is required, the applicants have knowledge of an additional language and greater work experience."
She added: "Gender bias in recruitment processes are based on stereotypes about productivity, rather than on prejudice.
"Employers vary their responses when women have more skills than other similar candidates, such as languages or a solid career or experience.
"In fact, the data suggest an almost complete absence of discrimination against highly qualified women without children."
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