In one experiment, about 200 undergraduates were asked to rate
paired applications for an imaginary midlevel managerial job. Both
female and male students rated mothers lower on competence and
commitment, recommended lower salaries for them, and judged them less
worthy of promotion than childless women.
In an even more convincing audit study, fictional résumés and cover
letters were sent to employers advertising midlevel marketing and
business job openings at a large Northeastern city newspaper. Childless
women received 2.1 times as many callbacks as mothers.
Fathers, however, were not penalized.
The Anti-Mommy Bias
And it's found in both men and women.