I think an awful lot of nicknames result from people simply being unwilling to repeatedly use (or remember) too many syllables when addressing or referring to someone.
So, how many is too many? One is clearly safe (no one shortens John and Ann out of laziness), and I think two is fine (David and Mary are good) but three is starting to get iffy (Jonathan and Bethany are probably more often shortened than not.)
Four is a real barrier. Alexanders must accept Al or Alex or Xander unless willing to be thought pretentious. Amelias are bound to answer to Amy.
But five? Are there commonly used five syllable names?
(I vaguely remember an SF novel where the aliens all had six syllable names. I genuinely had a hard time keeping the characters straight. Didn’t matter if they started with different letters, or even has NO letters in common. Its like my database for names only allows for a certain size of entry, and anything past that is simply discarded. I quit that book about a third of the way in, and the name irritation was a big factor.)
Added: obviously I am looking at names I come across in my daily life. For all I know, Malaysian first names may be routinely sixteen syllables long and they have no trouble using the full things all the time.
I don’t think that’s what it is - because while no one shortens one syllable names like John or Ann, they do get lengthened into Johnny and Annie and there are two syllable nicknames for two syllable names like Bobby (Robert) and Richie ( Richard) and even single syllable nicknames like Rob and Rich . I think at three syllables the nicknames are always shorter than the name- but I could be wrong about that. Most nicknames are meant to convey informality/familiarity - I wouldn’t call someone “Mike” if I was introduced to them as “Michael” , at least not until I was told to.
That’s usually how I parse them, but sometimes they can be clipped versions of lengthy names for convenience’s sake, or rough approximations of a non-English name that can be difficult for an English speaker. If a non-English speaker offers the nickname as a substitute, that’s fine, but I wouldn’t assume. I personally respond to any and all forms of my name, first or last, as I don’t care. To me, it’s just a word. But I wouldn’t assume others share my nonchalance about it.
My great grandmother’s name was Apolonia. There was an Apollonia co-starring in Prince’s Purple Rain. Other than that, though, I don’t run into those names.
Evangelina is one, though, that I do.
Maximilian if you don’t elide those last two vowel sounds.
I found a few candidates for five-syllable names. In a lot of cases, the number of syllables depends on whether adjacent vowels are pronounced separately or as diphthongs. None of the names below are very common in the US.
Bartholomeo
Bartholomeus
Bartolomeo
Massimiliano
Maximilian
Maximilien
Sebastiano
My daughters have names that are three and two syllables, respectively. We deliberately chose names that lent themselves to nicknames, since my name (Donna) doesn’t and I’d always wished it did. But neither of them has ever used a shorter nickname - at one point in her childhood, my younger one actually tried out a longer version of her name, and no one’s had trouble with the three syllables.
I worked in a school from 2008 to 2022, and one of the things I noticed was that kids, boys especially, are more likely to use their full names than they were in my youth. I saw a lot of Michaels and Davids and Roberts, but no Mikes or Daves or Bobbys.
A friend just told me her newest granddaughter is named Oceania, which she thinks is stupid. It’s supposed to be pronounced Oh-sea-an-e-uh. Friend is trying to establish her ‘use’ name as Shawna, but DIL objects.
I suggested she call the kid “Ocean-yuh” for a bit and maybe they’ll change their minds.
I’m with ya. I don’t mind the short form of my name, in part because I’m a III and so when my dad and grandfather were alive, being able to tell us apart quickly was useful (though that got complicated when all three of us were together, as my grandfather would get the full name, which was usually my dad’s; my dad would get the short name, which was usually mine; and I’d become just “P”).
But in school the French teachers invariably wanted to call us by the French versions of our names. I’d just say “That’s not my name” until they gave it up.
All of this might be why I’m pretty persnickety about not getting folks’ names wrong, including pronunciation of foreign names. Some folks just can’t seem to get it, even after years of working with someone!