The personal pronoun arose as a way to distinguish self from group

Evidence

Symbols and rudimentary language in turn stimulated the emergence of a self-concept, according to Mithen (and noted a century earlier by Friedrich Nietzsche in The Gay Science). Since communication probably often pertained to others in the group, our ancestors needed a way to differentiate themselves from others, so they came up with something like pronouns: me and her and him and you—and I. The personal pronoun “I,” Becker observed, served as a “symbolic rallying point” for self-consciousness by giving each individual a “precise designation” of herself or himself. — Sheldon Solomon, Jeff Greenberg, Tom Pyszczynski, The Worm at the Core, 285

Categorization

• XREF: Becker’s ‘symbolic rallying point’ resonates with the terror management tradition and with Zamyatin’s We, where the pronoun ‘I’ is precisely what the One State tries to abolish.
• CANDY: The idea that pronouns were invented before they were grammar — a light conversational nugget.