It only takes a few seconds for an argument to escalate.
Just as it only takes a few seconds for it to calm down.
A change of tone, a simple gesture of apology -- or, at least, understanding -- and peace can reign.
Sadly, things can sometimes go the other way. And that's what may have happened on this July 13 United Airlines flight from Las Vegas to Newark.
Former NBA player Eric Murdock wanted to move from his Economy Class seat and sit next to his son in an exit row.
A Flight Attendant told him it would cost more money.
However, he says a passenger who was going to sit there was happy to switch with him.
Then, he says, another Flight Attendant decided this wasn't fine at all.
What made things worse, says Murdock, is that a woman moved seats and this wasn't merely fine with the second Flight Attendant, but she was even offered a drink.
The woman was white. The Flight Attendant was white. Murdock is black.
Murdock says he asked the Flight Attendant why the woman's move was OK. He claims he was told to keep his nose out of it.
Murdock says in a lawsuit -- oh, yes, there's now a lawsuit -- that the Flight Attendant finally offered him a drink, adding the phrase "or are you going to boycott?"
For Murdock, this was "obvious race-baiting."
He wasn't alone. Another black passenger -- Brenda Williams -- stood up and took his side. She was, the lawsuit says, holding her phone.
The Flight Attendant seems to have assumed she was being filmed. After all, it's cellphone video that often brings such cases to prominence. Just ask United about the infamous time one of its passengers was forcibly dragged down the aisle of a plane.
Williams alleges that the Flight Attendant told her: "Erase the video now, or give me your phone! It's against the law to record me!"
You see, Williams has joined Murdock's lawsuit. The two didn't know each other before this flight. Now, their experience on United appears to have brought them together and they're asking for $10 million in their civil rights lawsuit.
Race has been a constant presence in Flight Attendant/customer disputes. Delta and American are just two other airlines who seem to have struggled in this area. The NAACP issued a travel advisory against the latter earlier this year.
But then there's the filming thing, which seems to have raised temperatures even further.
It rarely turns out well when a Flight Attendant tries to stop a passenger from filming them in the middle of a confrontation.
In essence, Flight Attendants are there to help create peace, rather than foment disturbance.
As for filming being against the law, well, I don't know about that. It may or may not be against that particular airline's rules. Illegal is something different.
You shouldn't interfere with the Flight Attendants performing their duties, of course. But sometimes passengers feel compelled to record them in action, just in case.
United's rules, though, allow for the filming of "personal events."
This event seems to have become very personal indeed. I asked United for its personal view. A spokeswoman told me:
At United, we proudly hold ourselves to the highest standards of professionalism and have zero tolerance for discrimination of any kind. We are looking into the allegations, and because of the pending litigation, we are unable to provide further comment.
Murdock offered this riposte to the New York Daily News:
In this divisive time people are emboldened to be the worst version of themselves. I never thought that I would personally be in this position, but neither will I back down. If I can use the fame and respect which I have gained to achieve social change I will.
In disputes such as this, it's worth being guided by the reaction of other passengers.
If United produces objective by-sitters who side with the Flight Attendant, that might make many wonder.
So far, however, we have two passengers who didn't know each other joining in a $10 million lawsuit. Which doesn't make United look too good.
I suspect Williams wishes she'd filmed the proceedings. It might have made her case easier.