By JUAN DE JESÚS BREENE

Looking to start some fireworks? Just ask people from various nationalities and cultural groups how much they suggest for tipping in a restaurant.

To many Mexicans, the typical response will range from 10 percent, if the service was good, to “I round out the bill or leave some change if it is a restaurant with servers.”

However, well-heeled Mexicans from urban areas will say that they leave between 15 percent and 20 percent, depending on the service.

For a lot of Americans, the answer is a  “minimum is 20 percent, why is there any question? ”

And many will add a comment like “and by the way, I worked as a waiter, so I sometimes leave 25 percent” or “if the service was great, I’ll leave more than 20 percent.”

Many Europeans are accustomed to not paying any tips at all, since in their countries gratuities are generally not given because the salaries of the servers are already high enough that such additional sources of income are not necessary. (They should remember that that is not the case in Mexico.)

Mix these three groups together for the discussion — especially in anonymous Facebook groups — and you have World War III on your hands.

Even educated and well-traveled folks who understand the finer points of cultural competencies from one culture to another often have quite strong opinions when it comes to tipping.

On a recent lengthy trip to Argentina, I tried to make sense of tipping in restaurants, where I happily ate three times a day, and over a month, I probably enjoyed the fare of close to 90 eateries.

I asked all kinds of locals, “What is the norm for tipping?”

In Buenos Aires, I consistently got a version of “just leave whatever you feel like, maybe around 10 percent; there is no formal norm.” Odd.

Even odder, when paying with a credit or debit card I got, “I’m sorry, our tax authority does not allow a gratuity to be included in the bill.”

I, of course, gave the tip in cash.

I got the feeling that in Argentina, the waitstaff did not seem too dependent on tips.

Even in tourist areas of the city like Palermo, when leaving a tip, which I always did, I was profusely thanked.

Restaurants in Argentina seemed to have a far lower server-to-customer ratio than in Mexico, so the service was naturally slower, but no one seemed to be in a hurry.

Food prices at restaurants was considered high for locals, but extremely reasonable for Mexican tourists.

Transfer that to Mexico’s tourist destinations, like Cancun, Playa del Carmen, Los Cabo, Puerto Vallarta, and the narrative changes drastically.

Waiters will openly tell you, if you speak in Spanish with them, “We prefer tourists.  They tip at least 20 percent, and many Americans, but not Canadians, will often tip 25 percent.”

Of course, Americans generally get the best service under that scenario.

Cultural and national convictions on tipping seem to be deeply rooted, independent of which side of the actual table on which the food is being served.

But whatever you personal views on the matter, tipping is a tangible way of saying thank you for someone taking the time and effort to make your meal worthwhile and pleasant.

So whether it is expected for not, it seems a no-brainer to show monetary appreciation to these hardworking servers.