I often hear or see the cliché “There’s a little Irish in all of us”.
Shouldn’t that be "There’s a little Irish in each of us?
BTW; I have absolutely no Irish in me, and don’t think to wear something green on St. Patrick’s day.
Peace,
mangeorge
Why should it?
If your question is whether speakers of standard American English (if you believe there is a single prestige dialect of American English) object to the phrase “There is a little Irish in all of us,” then the answer is no. It is hard to argue that a phrase is both a common cliche (particularly one not used jocularly) and a marked form. If your question is whether the English Grammar Rules in Plato’s Heaven allow the phrase, well, then you’re just being ridiculous.
No. The noun here is not “us” but “all of us”. “All of us” is used as a collective noun to refer the the entire population of the USA. It’s not a genetic reference, but a social one, and refers to the significant impact the Irish immigrants had on this country’s culture.
So it could be rephrased thusly: “As a culture, we’ve got a little Irish in us”.
Because that’s the way it sounds best to me.
Try this;
“There’s a cookie in the kitchen for all of you” vs “There’s a cookie in the kitchen for each of you”.
The former would have to be one very big cookie.
No, I think it’s referring to individuals, so strictly speaking, the OP is right. Of course, it’s an informal/idiomatic expression, and thus it’s not really shackled to the rules of prescriptive gramma.
Maybe my problem is that I’ve had very little of the Irish Experience. I much prefer roast beef with my cabbage.
Pretty Girl: “I’ve got a little Irish in me.”
Me: “Would you like a little more? Heh heh heh!”
Unless you have an authenticated pedigree going all the way back to Julius Caesar – on every branch of your ancestry – this is a statement that will be extremely difficult to prove.
Odds are great that by the time you go back six generations you’re going to locate at least one person of Irish descent, not to mention any other nationality, race, creed, ethnic persuasion or whatever.
I’m with Mister Rik - the ‘all’ is a collective noun, ‘of us’ is its constituent parts. “There’s a little bit of dinosaur in all living birds” is equally valid (linguistically, at least!)
You’re assuming a broadly European heritage there. A child of Japanese immigrants is unlikely to fit your description, for example.
You leave gramma out of this! What did she ever do to deserve such ingratitude? (Besides the shackles, I mean.) 
Your point is valid, of course, if that pedigree can be shown to have had no intermarriage (one must assume) – for six generations, in all branches of the tree – with any Europeans. Once you realize that six generations (64 individuals) must each have had no Irish connections, even if they are all isolated to the Japanese islands or the Australian Outback or the Siberian tundra, I still contend that you’ll need some serious authentication of that pedigree to be able to make that statement with any certainty.
The saying refers to association (Irish by osmosis ;)), not genetics.
So my statement could stand even if both parents were Irish.
Birds are, I think, direct desendants of dinosaurs. We’re not all, again I think, direct get of Irish.
Wait a minit! Connections outside my direct lineage would have no effect on my genetic makeup. My uncle’s (father’s sister’s husband) girlfriend’s illigitimate child has no direct relationship with me. Or did I misunderstand what you said.
Anyway, as I said. my statement (“I have absolutely no Irish in me”) has nothing to do with genetics.
This actually demonstrates why “all” works better. The point of the phrase, (that I have only rarely heard, anyway), is that there is a single “cookie” (link to Irish culture), that has been parcelled out to all of us rather than a specific strain of genetic Irish descent in each of our ancestries. YMMV.
I am not sure about the odds, actually, but I know that the “any other nationality” would not work for me if you are limiting it to six generations. If you mean “the odds” regarding a large section of the American populace, you might get away with that, but six generations is not that far back. I can get back to specific locales in Ireland and Germany in six generations because when my ancestors hit these shores they wound up in ethnic ghettoes and practiced endogamous mating right up to my parents’ generations. (Once we get to Ireland or Germany, I will make no claim that there was not some rogue Englishman or Scot or foreign visitor on my mom’s side or that there are no Slavs or French (or Mongols or Turks) on my dad’s side, but we can establish a single ethnic group for six generations with ease.) Similarly, the large number of immigrants from Eastern and Southern Europe would have tended to have excluded any Irish interference in their genetic chain within a mere six generations. (We are, of course, both ignoring immigrants from Eastern and Southern Asia, presumably due to their (current) low numbers in the population.)
What you’re all trying to tell me is that that there’s only one “little Irish”, and that it’s quantified only by the number of those who have it in them. Each of whom have the whole thing.
I need a joint.
I don’t know about “all” of anyone, but my point is that the expression is a reference to cultural ties and a desire for beer and laughter, (and perhaps melancholic music), rather than any genetic transmission.