It's all in the title.
I learned to use a fork the normal, at least the previous normal, with the tines up instead of down, also sort of replicating a spoon effect. When I see somebody using the fork upside down, I am thinking the food is going to fall off their fork. It seems like it is usually younger people eating with the upside down fork method.
A couple elements at play here. First being the American vs. Continental (with minor variations between British and European) style of utensil usage.
Lately the continental style is becoming much in vogue here in the States. Perhaps there is more exposure to more British and Euro television, or maybe an uptick in international travel over the last decade or so is bringing this style, more common elsewhere, home.
Using the Continental form, the fork stays in ones left hand, tines pointed down, and the knife in the right while eating. The handles of each utensil running inline with the hand, this method is sometimes called the hidden-handle method. The American style, which moves the fork to the dominant hand after the meat is cut, is found by many foreign observers to be clumsy or inelegant.
Which puts this matter on my list of things other countries are probably too quick to feel superior about. I have been told it looks clumsy, ineffective, and even that it makes the diner appear inept, and that the American style was a lax form that developed in the backwoods colonies. That the "zig-zag" of moving the fork left and right is distracting. The opposite is actually true.
When the American colonies were established the European method of dining prevailed among them. This meant no forks (except in Italy ... for some reason). A spoon or a knife was used, one or the other, in the right hand, or food was picked up and eaten with fingers. That is why particularly old table settings will include finger bowls for washing hands at the table.
Sometime in the early to mid 18th c. the use of the fork spread across Europe to the Colonies. At which time the style of holding the fork in the right hand (like any other utensil) was universal. the exception, of course is that when one is cutting ones meat, the knife is held and the fork passes to the off hand to hold the meat for cutting.
At the time, meat was most commonly served by a carver so there really wasn't need for a meat cutting knife in the hand at all times. For that matter, many working class households didn't have sharp knives for every setting. But in the case of being served something like a chop, etiquette would have the diner cut their meat and then return the knife to an idle station, or perhaps turn cut the meat of the lady or elderly or otherwise invalid person (antiquated viewpoints which are not my own) to the diner's left or right. This is the correct form of the American Style. One should not be cutting a piece of meat, switching the fork to the right hand, eating the morsel, then resetting the fork to the left hand and cutting another piece of meat. I don't think I've ever seen an American doing it that way but this seems to be a common impression the British have of our eating habits.
So how did the Continental System develop? The French. The French monarchy, beginning with Louis 14th, used etiquette as a means to control stroppy nobles. Changes in 'courtly' behavior were published regularly and compliance was expected. One way to show off French superiority was to make sharp cutlery a standard item at each place setting, something that came to pass around the time of the American Revolution. And to make a bigger spectacle of having a knife for every diner, it was decreed that the proper way to eat would be for the knife to be in use constantly from the beginning to the end of the meat course. Cut a piece, eat a piece, cut a piece, eat a piece... etc... Because France was considered the height of polite society and fashion (even in England ... even while England and France were at war...) the French style spread quickly across Europe. A large reason for this may have been that most of Europe was 'united' under Napoleon, but for whatever reason it stuck.
The newly United States never picked up the French style. Around the time the US had time to consider it, they were just 'done' with France anyway and I think they figured they would just keep on eating like they have been because it worked.
Which way is better? I find the Continental Style distracting. Not because of which hand the fork is in or tines up vs down. Just cut your meat, put the knife down, and eat. It also bugs me that the same posture is adopted for food that doesn't need to be cut with a knife. A fish course, for instance, should be eaten with a fork in the right hand; whatever side of the Atlantic you're on.
To the bloke (a good friend really) that suggested the American style looked clumsy or inept ... I asked him to describe how they eat peas in England. The beet red version of him acknowledged the touché. If you've never seen it ... okay ... food that can't be stabbed with the fork are supposed to be marshalled with the knife onto the back of the fork (the convex top of the fork if the tines are pointed down). Like mashed potatoes and such, it gets sectioned off by the knife and then ... mooshed into the back of the fork and then brought to the mouth. About the clumsiest way to eat, you might think, that is until it's time to eat peas. They roll off the back of the fork. So the English-Proper way to eat them is to smash them against the plate until they can be mortared onto the back of the fork.
So there you go. The American style has been in practice since the beginning of the fork's general usage and was the dominant style across Europe and England. The Continental style is a more modern invention. It was given to the world by the French as a way to show of and also make eating just a little bit more like ballet. I won't say the American style is better, unless someone asks me, or criticize someone for using the much more common Euro-method, unless they ask for it.
Thank you for coming to my Ted Talk, brought to you by Adderall and Snow-Day boredom