A thornier question, though, is whether employers should use Banaji's test. Here the stakes are high on both sides. In a lot of jobs—judges, police officers, welfare officers, hiring managers, and others as well—biased people can do real harm. On the other hand, if a test shows an applicant is biased, but you have no evidence that he has actually discriminated against anyone, would it really be fair not to hire him? This is where the distinction between implicit bias and actual discrimination becomes most important. Since the test is not perfectly predictive of actual behavior, the risk of a false positive here is real. If you screen somebody out of a job who would not have actually behaved in a discriminatory manner, you've done them wrong.
Using the implicit bias test for employment screening, then, goes too far (and it's easy to imagine the legal challenges). But employers should be able to use the test to assess employees once they've been hired. Ideally, an employee's individual result would be revealed only to him or her (employers could get aggregate reports so they could better make decisions about how to reduce bias in the workplace). One reason to encourage employers to give the test is that, as Berkeley psychologist Jack Glaser points out, just taking it may sometimes be enough to convince people they are prejudiced and should try to change. It's called "unconsciousness raising"—if you know what your unconscious is doing, you may work to override it.