When hiring managers made a mistake -- by hiring the candidate with a lower math-test score during rounds in which candidates were not allowed to brag about their scores -- the mistake favored men more than 90% of the time, Reuben said.
The results, especially the minimal change in bias caused by the inclusion of test scores that gave an indication of competence, show that the mistaken belief that women are less competent in STEM topics than men is deeply seated and difficult to shake, "even when confronted by evidence to the contrary," Reuben said.
Gender bias and discrimination are serious social problems, and gender bias is a direct threat to individual companies and the US economy as a whole, he said. "The end result is… a detriment to these companies for hiring the less-skilled person for the job."
The bias against hiring women worsens a skills shortage that has already outstripped the National Action Council for Minorities in Engineering's once-alarming prediction that the US would need a million more working technologists by 2018. In reality, according to the job market analysis firm Burning Glass Technologies, demand for technical skills was already so great in 2013 that, for every college student graduating with a technology degree, there were 2.5 unfilled jobs requiring a technology degree.
The economics writer Cynthia Than countered Reuben's pessimism in a March 3 blog in Quartz. She wrote that women are more interested in STEM fields -- and are entering both jobs and schools in higher numbers -- than in the past.
Nevertheless, the study concluded that, as long as American hiring managers reject job candidates of one gender twice as often as the other -- and for less reason -- their employers and the economy as a whole will suffer just as they would at the loss of any other resource.
"Raising awareness of this problem is a step in the right direction," Reuben said in the press release. "Hiring managers need to disassociate themselves from general stereotypes and focus on the candidate. Leaving your personal experiences out of the process will likely land you the best candidate. Otherwise, you are hurting your company."