Plato, Laws 681b

ἔθη ἄττα ἴδια διὰ τὸ χωρὶς ἀλλήλων οἰκεῖν, ἕτερα ἀφʼ ἑτέρων ὄντων τῶν γεννητόρων τε καὶ θρεψάντων, ἃ εἰθίσθησαν περὶ θεούς τε καὶ ἑαυτούς, κοσμιωτέρων μὲν κοσμιώτερα καὶ ἀνδρικῶν ἀνδρικώτερα, καὶ κατὰ τρόπον οὕτως ἑκάστους τὰς αὑτῶν ἂν αἱρέσεις εἰς τοὺς παῖδας ἀποτυπουμένους καὶ παίδων παῖδας, ὃ λέγομεν, ἥκειν ἔχοντας ἰδίους νόμους εἰς τὴν μείζονα συνοικίαν. πῶς γὰρ οὔ;

and also some customs derived from its isolated condition and peculiar to itself. As those who begot and reared them were different, so these customs of theirs, relating to the gods and to themselves, differed, being more orderly where their forefathers had been orderly, and more brave where they had been brave; and as thus the fathers of each clan in due course stamped upon their children and children’s children their own cast of mind, these people came (as we say) into the larger community furnished each with their own peculiar laws. Of course.