@layman,
One of the most fundamental (1 of 3) tenets of logical thought is that of (self) "identity," i.e,, that "A = A."
An interesting study of children on this was done quite a while back. At an early age (say 3-4) kids can't really grasp and apply the concept of identity. They are shown two glasses, each with an (identical) amount of liquid in them and asked which has more.
One glass is a long, narrow container like a test tube, and the other is a short, large-diameter mug.
They invariably say the narrow glass contains "more" because the liquid in it goes "higher."
Then the liquid in one glass is dispensed with and the water remaining in the other is poured into it. This is done repeatedly as the kids watch and the kids still always say the test tube is the one with more water in it, even when the
exact same water (and therefore an identical amount) is poured from one to another.
Kids can't typically grasp this until later ages like 5 or 6.
Certainly they are not "born with" an innate concept of "equality" as Plato would claim.