Single moms don’t face penalties at work in the same way married mothers do, according to the findings. And at the same time, single dads don’t benefit in the workplace the way that married fathers do.

Past studies in sociology have established the “motherhood penalty” and the “fatherhood premium.” Research has shown that in the US, mothers are subject to a net wage penalty of 5-7 percent per child and are often perceived as less competent and less committed. As a result, they end up in “mommy-track” jobs with fewer opportunities for career advancement and financial security.

Conversely, some research suggests that men reap benefits as a result of becoming fathers and might see a boost in pay, as well as an improvement in how others perceive them at work.

Breadwinners and caregivers.

Past studies say the difference in treatment between moms and dads results, at least partially, from enduring gender stereotypes that women are primary caregivers, whose attention is largely focused on their children, while men are breadwinners, whose focus is on financially supporting their families.

But what happens when there is only one parent in the picture? That’s what University of Arizona sociology doctoral student Jurgita Abromaviciute wanted to find out.

Most existing research on the motherhood penalty and fatherhood premium doesn’t explicitly take into consideration parents’ marital status. It’s possible that people simply assume parents of young children have a spouse, says Abromaviciute, who presented the work at the American Sociological Association Annual Meeting in Philadelphia.

In an experimental study, Abromaviciute found that when parents are not married, the motherhood penalty and fatherhood premium seem to disappear.

“The penalty does not apply for single mothers the way it applies for married mothers,” Abromaviciute says. “When a woman is known to be single and when she has children, then in addition to being a caregiver, she’s also a breadwinner. So, in addition to caregiving, she now also has to provide for her family and she has no one to fall back on.

“My research shows that single mothers are not perceived as less competent or less committed than single childless women, and they are not less likely to be hired or promoted compared to their childless counterparts. In other words, while the motherhood penalty holds for married mothers, it disappears in the subsample of single mothers.”

While single moms don’t face penalties, they don’t get the premium either, Abromaviciute says. Neither do single dads, it turns out.

“Single fathers, in addition to being breadwinners, are caregivers to their offspring,” Abromaviciute says. “Likely, this triggers an assumption that they are more focused on their family than a married father might be, which eliminates the fatherhood premium.”

Marriage as a cue.

Abromaviciute bases the findings on an experiment in which she asked 160 college students to evaluate job application materials—including a resume and notes from a human resources interviewer—from fictitious job applicants with comparable experience, all applying for an upper management position with a communications company.

Participants learned of applicants’ gender, marital status, and parental status. After reviewing the materials, they were asked to evaluate the applicants through a series of questions.

Abromaviciute’s experiment replicated existing evidence that moms experience a motherhood penalty and dads a fatherhood premium when they’re married, but found this is not the case when they’re presented as single.

“For the subsample of single mothers and single fathers, there’s no premium or penalty,” she says, “which suggests that marital status operates as a strong status cue that, combined with gender and parenthood status, leads evaluators to make assumptions about one’s anticipated performance at work.”

Abromaviciute hopes to replicate her results with a broader demographic of study participants. She’s also interested in looking at how results might vary across a broader swath of the labor market.

“One caveat I’m making is that the single parents in this study were presented as driven, ambitious, and accomplished,” she says. “Also, this was an upper management position. In real-world situations, single mothers often face structural challenges—lack of social support, lack of education, lack of valuable and relevant workplace experience, as well as limited time for hobbies and interests presented on resumes used in the study.

“So, these findings likely apply for middle-class applicants and employees. We don’t know what happens in working-class jobs.”