Cathy O’Neil is a Bloomberg Opinion columnist. She is a mathematician who has worked as a professor, hedge-fund analyst and data scientist. She founded ORCAA, an algorithmic auditing company, and is the author of “Weapons of Math Destruction.” Read more opinion LISTEN TO ARTICLE 4:14 SHARE THIS ARTICLE Share Tweet Post Email

Photograph: Keystone/Getty Images Photograph: Keystone/Getty Images

If you applied for a job recently, there’s a good chance that you were subjected to a personality test. In some areas, the tests have become ubiquitous as U.S. employers seek ways to make the hiring process more efficient.

That’s unfortunate, because the tests might be filtering people out according to traits that bear little or no relation to their potential as employees.

New types of vetting have proliferated as the job application process has moved online. In white-collar industries, hiring managers build and deploy algorithms that decipher resumes, check people’s social media profiles or have others do so, and even use artificial intelligence to analyze interviews. For minimum-wage work, personality tests are designed to find the people most likely to stay in jobs, reducing the turnover that can be a major expense for call centers and retail stores.

Ideally, all the innovation saves time and money for everyone. But hiring algorithms don’t always perform as advertised. There’s reason to think they tend to repeat and even amplify historical patterns of discrimination – though this can be hard to ascertain, given that their code is usually proprietary and regulators don’t have the technology to test it even if they could.

Personality tests, too, can be biased in undesirable ways. They can, for example, filter out people with a history of mental illness – becoming a sort of health exam, which is prohibited as part of the hiring process under the Americans with Disabilities Act. Several years ago, CVS agreed to remove certain mental-health-related questions from its pre-hire questionnaire after a Rhode Island human rights commission found “probable cause” to conclude that they violated state law.

More recently, job applicant Kyle Behm personally experienced the discriminatory effects of personality tests (as reported in the Wall Street Journal). As a college student in 2012, he sought work at a Kroger store but failed a test designed by the company Kronos, which licenses hiring software to many large stores.

Behm was unusual in a few crucial ways. First, he had a friend at Kroger who told him he had failed (most people never hear back). Second, he recognized some of the questions from a mental health assessment he had taken when being treated for bipolar disorder. Third, his father, Roland Behm, was a lawyer – a professional to which most applicants for minimum-wage jobs don’t have access. After getting Kyle to apply to six more companies that used the same personality test, which he duly failed, Roland filed complaints – some jointly with the Equal Employment Opportunity Commission – against all seven companies for violating the ADA.

Setting ADA violations aside for a moment, there’s increasing evidence that personality tests aren’t very successful at finding good employees. A recent study found that the test results are poorly correlated with job performance, especially when compared with other types of assessments.

So why use them? Roland Behm offered one convincing reason: Maybe all employers really want is a tool to help them reduce the huge pool of applications they receive for any given position. Whether or not personality tests actually work, they fulfill that basic requirement.

Thanks to the lawsuits, some companies appear to be reconsidering their practices. One of the companies Kyle applied to, Lowe’s, said it had changed its online application process “to ensure people with mental health disabilities can more readily be considered for opportunities.” The statement was issued jointly with the Judge David L. Bazelon Center for Mental Health Law, an advocacy organization for people with mental health disorders.

Roland noted that the change could be about more than avoiding litigation. People with some history of mental illness comprise a significant portion of U.S. consumers: Fully one in six Americans take a psychiatric drug. So companies have a good reason to avoid alienating a large group of people who, if they’re being excluded from work, might also take their business elsewhere. Better to hire them and welcome them into the community.

As for personality tests, we should make sure that they’re working not just for employers but also for the public at large. Considering their pervasiveness, they could systematically exclude an entire population with disabilities from work – precisely what the ADA was meant to avoid. Let’s hope other companies follow the example of Lowe’s and take steps toward avoiding that outcome.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.