This post was originally published on Forbes Online October 6, 2017

It didn’t take Rex Tillerson’s reported mega–gaffe (originally reported by NBC news) — allegedly calling his image-sensitive boss a “moron” at a Pentagon meeting — to acquaint us with the idea that it’s a bad idea to humiliate your boss in public. No doubt Tillerson, who neither confirmed nor denied the report as of this writing, knows that as well and never intended his muttered or sputtered comment to be public. The hot water he’s swimming in does remind us that there’s no such thing as “private” any more. It’s wise to proceed on the principle that you should always consider yourself in “public” when mocking or insulting your boss.

Less obvious, perhaps, is the principle that a leader should never humiliate anyone.  Period.  Never as a strategy, certainly. Never on purpose. Never “by accident” if you can possibly avoid it.  And if you do humiliate someone inadvertently, make amends quickly.

Here’s why humiliation is  so damaging to both the leader and the led.

There is no human immune to the feeling of humiliation, a sickening flush of exposure and shame when someone makes us look different, foolish, stupid, ugly or unlikeable. I suspect it’s a remnant of our evolutionary hard-wiring designed to reinforce our ability to belong to the group, which back in the day  was essential to survival.

Acting and appearing in ways that meet social norms still has survival value. Correcting your peoples’ odd, inappropriate or culturally unacceptable behavior has value in business, as does, obviously, delivering criticism. But do it tactfully, or in private. Using humiliation to change people’s behavior is not just costly — it leads to employee disengagement or departure for starters — it also does not work.

A person who feels humiliated retreats automatically to a defensive position and can’t listen constructively. So, their behavior isn’t going to change; they’re just going to hate and mistrust you.  Their loyalty will be weakened  and their motivation to succeed and make you look good will be diminished, if not damaged irreparably. Inevitably, humiliation is followed by anger or even rage, which becomes  even more dangerous when that anger is suppressed and out of the person’s awareness.

There is one exception to humiliation having an entirely negative effect. I know people who have been humiliated by the consequences of their own bad behavior.  That deep sense of exposure and failure can be a powerful motivator to change and succeed.  But this only happens when the person sees herself as coming up short compared to her own ambitions, standards and ideals — not when the humiliation is driven by someone else.

There are some obvious ways leaders humiliate people — yelling at them publicly, mocking them, criticizing them contemptuously in front of others.  The Pittsburgh Post Gazette recently reported on a document written by disgraced Congressman Tim Murphy’s chief-of-staff.  It makes for wince-inducing reading, amounting to a manual of “what not to do” as a leader.  The memo describe Murphy’s humiliating patterns of behavior towards his staff including putting them  in a position when they can’t succeed and then yelling at them for failing, asking the impossible and getting enraged when it’s not delivered and refusing to adjust his behavior when grave concerns are brought to his attention.

Meanwhile, the now too familiar reports of sexual harassment and bullying in Silicon Valley, the offices of media moguls and on politicians’ platforms also provide an obvious “don’t” list for the leader who accepts that humiliating people is bad for business, whoever the target is.  This means, among other things, do not comment gratuitously or publicly on someone’s appearance or behavior.  This includes breast size, weight, dress, voice, disability, quirk, height, tic, or hand size.

Paradoxically, it may be harder to avoid humiliating people in the obvious ways I just outlined, since excessive anger, entitlement, corporate culture, alcohol and other disinhibiting forces are often implicated when a leader habitually humiliates others.  And these are tough problems to tackle, not responsive to simple do’s and don’ts, or as we know, well-written employment policies.  A leader who uses humiliation regularly needs to be do some serious self-examination and change, or be confronted and tackled by peers or superiors and advised to alter his behavior or get out.

There are less obvious ways though that even a well-intentioned leader can inadvertently humiliate people. Because these missteps tend to be driven by oversight or hurry rather than character, they are more avoidable or correctable.

Here are three best practices to avoid inadvertently humiliating people on your team:

1. Make sure that everyone personally affected by a change is informed—preferably personally—before news goes out to a larger audience.  I’ve seen project managers learn that their project was disbanded or re-named through emails sent to a larger group.  When I’ve asked the leaders involved why they didn’t let the effected person know beforehand, they often just didn’t think about how that person would feel and simply wanted to move forward. It’s worth the time it takes to call each manager impacted by a change before the whole company learns about it. You’re not asking their permission, but rather communicating that you know they might have feelings about it.  Nothing is more humiliating for a manager than learning about a change at the same time his team does.

2. Believe, or act as if you believe, that everyone is doing the best they can. I learned this from one of the most extraordinary leaders I know, who always projected a sense of calm and purpose no matter what the crisis swirling around her.  I asked her how she could deal with the immense internal politics she faced every day in the large enterprise she ran and she said, “I just assume everyone is doing the best they can.” That doesn’t mean you can’t fire someone whose best isn’t good enough, but don’t get angry and humiliate them.

3. Back off when you’re angry or frustrated. You can only correct people effectively when you are calm.

Finally, apologize when you’ve humiliated someone.  A video was leaked of MSNBC host Lawrence O’Donnell swearing in an angry rant due to technical difficulties during a September show.

O’Donnell followed up promptly with an apology tweet, and I hope with a personal apology to his technical staff, none of whom, presumably, wanted the show to go badly.  What I like most about O’Donnell’s tweet is “a better person would’ve had a better reaction.” He’s right, and offers no defense.  In doing so, he humanizes himself without offering a justification, reminding us we all wish at times we were better people.