Humans are not unbiased observers and decision makers. I’m not talking here about prejudice based on protected categories. I’m talking more generally about systemic flaws in how our brains interpret and act upon information. Take for example the Ebbinghaus Illusion. There are two red circles in the image below. While people consistently see the left one as smaller, they’re the same size.

Scientists spend a lot of time studying how and why we consistently misinterpret the world around us. Michael Lewis (in The Undoing Project) and Nobel laureate Daniel Kahneman (in Thinking Fast and Slow) discuss these issues in depth.

Sexual overperception bias provides an example that’s relevant to employment law. It occurs when a person mistakenly perceives that a member of the opposite sex is sexually interested in him or her. Studies (like this one) show that men are far more likely to make this mistake than women. In other words, men are more likely to believe that a woman is interested in them sexually when that is not the case. There’s even a study that suggests that men in positions of power are more likely to make this mistake.

It’s obviously hard to change biases that may be ingrained through evolution. But good luck arguing in court that the alleged harasser you represent is just wired that way. Employers need to educate supervisors that, whether they think someone is interested or not, pursuing workplace romance can be disastrous. They can use harassment prevention training to make this point.

The training doesn’t need to get into detail regarding cognitive biases. It does, however, need to emphasize the tremendous downside of supervisors pursuing relationships with subordinates. The #MeToo movement provides plenty of examples of men who acted inappropriately toward subordinates and suffered the consequences. Instead of trying to undo biases that may have an evolutionary basis, make sure that supervisors understand the financial, emotional, organizational, and reputational costs of making unwelcome advances to their subordinates. I’m not ignoring the costs paid by victims of harassment. I’m saying that for harassment training to be effective, supervisors need to understand that the risks of making unwelcome advances far outweigh any perceived upside.