So, let's check the etymology of the 3 words. I'll use the Online Etymology Dictionary.
people (n.)I see the Online Etymology Dictionary is trying to scare us away from "individual" by quoting Hitler, but how do I know they're not communists? Let me switch to the Oxford English Dictionary (which, unfortunately, I can't link to). It's a much richer source of quotes and it always gives us the earliest quotes that can be found.
late 13c., "humans, persons in general," from Anglo-French people, Old French peupel "people, population, crowd; mankind, humanity," from Latin populus "a people, nation; body of citizens; a multitude, crowd, throng," of unknown origin, possibly from Etruscan. The Latin word also is the source of Spanish pueblo, Italian popolo. In English, it displaced native folk.
Meaning "body of persons comprising a community" first recorded late 13c. in Anglo-French; meaning "common people, masses" (as distinguished from the nobility) first recorded c.1300 in Anglo-French. Meaning "one's own tribe, group, etc." is from late 14c. The word was adopted after c.1920 by Communist totalitarian states to give a spurious sense of populism to their governments...
early 13c., from Old French persone "human being, anyone, person" (12c., Modern French personne) and directly from Latin persona "human being, person, personage; a part in a drama, assumed character," originally "mask, false face," such as those of wood or clay worn by the actors in later Roman theater. OED offers the general 19c. explanation of persona as "related to" Latin personare "to sound through" (i.e. the mask as something spoken through and perhaps amplifying the voice), "but the long o makes a difficulty ...." Klein and Barnhart say it is possibly borrowed from Etruscan phersu "mask."...
Of corporate entities from mid-15c. The use of -person to replace -man in compounds and avoid alleged sexist connotations is first recorded 1971 (in chairperson). In person "by bodily presence" is from 1560s. Person-to-person first recorded 1919, originally of telephone calls.
"single object or thing," c.1600, from individual (adj.). Colloquial sense of "person" is attested from 1742.
A majority can never replace the individual. ... Just as a hundred fools do not make one wise man, a heroic decision is not likely to come from a hundred cowards. [Adolf Hitler, "Mein Kampf," 1933]Latin individuum meant "an atom, indivisible particle;" in Middle English individuum was used in sense of "individual member of a species" from early 15c.
The earliest use of the noun "individual" to mean "single human being, as opposed to Society, the Family, etc." is from 1626:
J. Yates Ibis ad Cæsarem ii. 12 (margin) , The Prophet saith not, God saw euery particular man in his bloud, or had compassion to say to euery Indiuiduall, Thou shalt liue.And here's one from 1899:
J. Monro Gibson in Expositor Feb. 144 It will not be as Churches but as individuals that we shall all stand before the Judgment seat of Christ.The oldest quote for "person," meaning "An individual human being; a man, woman, or child" is from 1225:
Ancrene Riwle (Cleo. C.vi) (1972) 236 Abute sunne liggeð six þinges. þet hit hulieð..Persone. stude. time. Manere. tale. cause. Persone. þe dude þe sunne oðer wið hwam me hit dude.That's a tad hard to read, but I quoted it anyway, because I liked the "dude." If we crank forward to 1440, we get:
R. Rolle Eng. Prose Treat.... The fifte comandement es þat ‘thou slaa na man..’ And also here es forboden vn-ryghtwyse hurtynge of any persone."Person" is interesting in that it has been used to denote "A man or woman of high rank, distinction, or importance" and, alternatively, "An individual considered to be of low rank, status, or worth." An old example of the former is:
1709 J. Addison Tatler No. 116. ¶1 She had a Mind to look as big and burly as other Persons of her Quality.And the latter:
1704 Swift Tale of Tub Ep. Ded. 2 It is amazing to me, that this Person should have Assurance in the face of the Sun, to go about persuading Your Highness, that our Age is almost wholly illiterate.Another function of the word "person" is to distinguish a human being from things or from other animals, as in:
1678 T. Sprat Serm. preached before King in Serm. (1710) 168 A zeal for persons is far more easy to be perverted, than a zeal for things.Finally, "people." I'd forgotten about the singular, colloquial usage, noted in 1891:
J. Maitland Amer. Slang Dict. 201 ‘He is great people’ is used in a commendatory sense of anyone.OED also quotes "The Sopranos":
1999 J. Cahill Guy Walks into Psychiatrist's Office in Sopranos (television shooting script) 2nd Ser. 24 Lee's good people. He came all the way from the village on an hour's notice.But basically, "people" is a singular noun and we're interested in it here for the way it's used interchangeably with person/individual when there are more than one persons/individuals. So I have to exclude the definitions that go with quotes like "I speak to the people as one of the people." (1771 ‘Junius’ Stat Nominis Umbra.)
I want the usage that you see in the song "People" when 2 individuals realize that each was a half and they've become whole, they add up to people. So even 2 is enough to make this kind of people. We're not talking about the masses or the populace or "We the People," just any number of human entities exceeding one (or one-half if these entities are the luckiest people, people in love).
I wish I could show you the long page in the OED that I'm combing through. I don't think any of the definitions fit what I'm looking for, even though it is exceedingly common in American speech.