Birds of a feather flock together

The meaning is that beings (typically humans) of similar type, interest, personality, character, or other distinctive attribute tend to mutually associate.

Plato's original is: Εγώ σοι έφη, νη την Δία, εγώ ω Σώκρατες, γε μοι φαίνεται, πολλάκις γαρ συνερχόμεθα τίνες εις ταύτο, παραπλησίαν ηλικίαν έχοντες διασώζοντες την παλαιάν παροιμίανJowett gives this as: I will tell you, Socrates, he said, what my own feeling is.

[5]However, Jowett here is taking a liberty in rendering Plato's phrase into idiomatic English of his time; the Greek original has nothing about birds, and it is not known what "old proverb" is referred to.

"[6] But Jowett's work was quite influential and respected in his time[7] and after[8] and his translation of Plato was the standard for about a century and is still used,[citation needed] putting the proverb in the mouth of a character (Cephalus) to be read by generations of students and scholars.

"[14] In Swedish, "lika barn leka bäst" ("children that are alike play the best [together]") is also sometimes translated into idiomatic English as "birds of a feather flock together.

The original Mishnaic Hebrew proverb is "לא לחינם הלך זרזיר אצל עורב, אלא מפני שהוא מינו" (Not for nothing went a starling with a crow, but because it is its kind) (Hullin 65, A).

[15] In Finnish, "vakka kantensa valitsee" (bushel will choose it's lid) is an idiom with a similar meaning and it's also sometimes used as a local alternative to the English "birds of a feather flock together".