The origins of giving the finger

There's a great Jerry Seinfeld bit (video below) where he points out (ahem) the absurdity of giving the finger. "It's a finger, what does it mean? he says. "Someone shows me one of their fingers and I'm supposed to feel bad." But really, what are the origins of this obscene gesture? Apparently, we have the ancient Greeks to thank (blame?).

The gesture "probably relied on the use of the middle finger to represent an erect penis," writes University of Windsor ancient social history researcher Max Nelson.

From CNN:

The Greek playwright Aristophanes was also purportedly a fan of the gesture, referring to "the long finger" in several of his plays.

In his comedy "The Clouds," written in 419 B.C., a caricature of Socrates attempts to instruct the debtor Strepsiades about poetic meter. Strepsiades makes a crude joke about using a different finger to create rhythm. Translators of the text usually conclude that Strepsiades gesticulates with his middle finger (or, in some translations, reveals his privates) to refer to masturbation, said Nelson. Whatever the intent, the Socrates character responds with disgust.

The gesture eventually made its way to ancient Rome, where locals likely called it "digitus impudicus" – the indecent digit