I think etiquette is more than manners.
Consider visiting another country. You should adhere to the etiquette of that country. Even if you are well mannered you might still, inadvertently, come across as rude. Each society has some built in expectations which I think can be listed under “etiquette.”
Should an American woman walk down a street in Tehran wearing Daisy Dukes shorts and a tank top? Might be fine in the US but not in Tehran no matter how polite and well mannered she is.
It’s what most ladies do these days, and not just at formal events. The timepiece is their phone, and it lives in their purse.
One of the dumbest American habits. My mother always brushed it off by saying “We eat European style” (cut with the right, eat with the left).
Women do not wear watches as an accessory?
I have a cell phone which keeps way better time than my watch but I still wear a watch. I do it because I think it looks good (and I like watches).
When I was in college I would occasionally eat European style, partly for practice (I was an aspiring actor and wanted to be prepared in case I ever needed to do it for a role) and partly to see how long it would take for my friends to start looking at me funny.
Suppose you meet an oil sheik, and you hope that he will offer you an exiting job with a 7-figure salary.
If he sees you eating with your left hand, he will probably never make such an offer.
And you may never know why.
Miss Manners is not writing for the people at the top of the social ladder.
She is writing for the people hoping to climb.
She is trying to help you avoid scorn from the snobs above you, and conflicts with the people around you.
Some minor points: I can’t find anything online that says that Judith Martin used to be a humor columnist. She’s worked as a journalist for a long time and started doing her present column in 1978. The first name of Petri is spelled “Alexandra”. Judith Martin has doubtlessly changed some of her views expressed in her column, just as many of us have done since then. The Wikipedia entry on her says that since August 29, 2013, her children, Nicholas and Jacobina, help her in some way on the column. Perhaps they tell her about the views of younger people that she should learn about. I’m not qualified to answer any questions about manner and etiquette.
When you eat soup, in which hand do you hold the soup spoon? If you’re right-handed, why on earth would you hold it in your left? And indeed, I believe it’s considered “proper” to use the dominant hand, for obvious reasons.
So why on earth would you not do the same with a fork when eating solid foods? That addresses the strange European habit of holding the fork in the “wrong” (non-dominant) hand, but the American custom of constantly switching the knife and fork seems to me to be even more nuts. “Sawing back and forth”? Sure, when I’m doing carpentry work I hold the hacksaw or circular power saw in my right hand. Cutting off a piece of steak or roast beef doesn’t rise to that level of motor skill! There are a lot more intricate actions involved in scooping up food and delivering it to the mouth than in sliding a knife across a piece of food on a plate.
I was always perplexed by the US custom of switching the knife and fork but then I discovered that the Europeans did it wrong, too. There’s nothing even remotely difficult about holding the knife in the left (non-dominant) hand.
For you, perhaps. In my case, my left hand is so clumsy with a knife that I honestly consider it unsafe.
I guess after a lifetime of eating that way, one gets good at it! 
It’s certainly more efficient to not have to switch the knife and fork around, while also at the same time using the fork more naturally in one’s dominant hand.
But what happens when an assassin comes for you? The seconds it takes to switch the knife to your fighting hand could be fatal! I’m certain that isn’t the reason for the method, but it makes a decent folklore explanation.
I stab him with the fork!
She is a humorous columnist, which is perhaps not quite the same thing.
Others have covered it above, but she is not writing a serious etiquette column for people who want to get etiquette right. She is writing a humourous etiquette column that nevertheless is thoroughly researched and fact-based (i.e. she knows her stuff). It’s more of a sociological and historical discussion of etiquette than it is a proscriptive guide.
She has also, in my opinion, declined a good deal since the column started being co-written. Her work as a writer, Miss Manners and otherwise, was excellent in the 20th century, but the current Miss Manners column is a shadow of its former self.
Young women mostly don’t. I wear a watch because i find it more convenient than pulling a phone out of my pocket, but I’m old.
I agree with this. But hey, she’s pretty old. She deserves to retire.
I’m sure that’s true today, at least for most events. I have no idea how smartphones are handled at evening dress dinners.
That is, nevertheless, not what Miss Manners meant, since the original question was asked and answered in 1993 and contained a mention of watches in purses. To be kind, Miss Manners might have been making a sly and satirical allusion to stuffing a watch down one’s cleavage. As all of you must know by now, I am not kind, and I continue to boggle at that suggestion.
I typoed it and I apologize to Ms Petri, whose column I greatly admire and I say that if you have any access to the Post and haven’t been a regular reader of her column, what the hell are you waiting for?
As for Judith Martin, she wrote a humorous column on politics for the Post, starting around 1965. Several dozen examples of which were collected for the 1972 book The Name on the White House Floor. Martin may not have been the Post humor columnist; that would be Art Buchwald. I’d put her work closer to that of Russell Baker’s column for the Times. His books of columns also line my humor shelves. So definitely a humor columnist.
And I cut my food with my knife in my right hand. Always have, always will.
I am ambidextrous and have always held my fork in the left hand and the knife in the right hand because that’s where they are in the place setting. I was really surprised to learn that many people swap the fork between hands. I may have learned that from Miss Manners, in fact. I guess i didn’t spend a lot of time watching exactly how other people eat.
I should use chopsticks, Id probably eat less at
mealtimes as I’m hopelessly klutzy and slow with the sticks.
If you did that with something like this the chef would probably not even bring out the next course as he wept.
https://www.facebook.com/photo/?fbid=3021482567947817&set=pcb.3021484461280961
Oh heck, Miss Manners guide to excruciatingly correct behavior is humor. I mean, there’s useful advice in there, but it’s a very funny book
I know I read it way back when, though when is a long time ago. A funny book about advice is not the same as a humor book about advice was my decision. My collection, my rules.
Collections are demanding; the lines about what goes in and what doesn’t always need tending. Too bad there isn’t a humorous advice book about book collecting.