That "shame on you" gesture --

[InternalDialogue]

you know, the one where you run one index finger down the other like you're scraping cake frosting off of it?

What's the origin of that? It makes no sense to me.

[Haole Girl]

1. I don't know

But it's funny.

[trof]

2. Like whittling your finger.

Yeah.
Wonder where that came from?

[InternalDialogue]

4. There's got to be some symbolism.

Like, "Here's what you deserve: This dry skin, wiped from my finger! Take that, shameful dog!" <wipe, wipe>

[DemBones DemBones]

3. Brushing the shame off onto you.

I seem to recall it being used to brush cooties onto other kids back in grade school. Imaginary cooties, of course.

[Gormy Cuss]

5. "Shame Fingers"

"The shame fingers gesture is a deliberate one that lets another--usually a child -know that you are reprimanding her. Experts posit that rubbing of the fingers symbolizes the friction between the shamer and the shamed. Often, the phrase "Shame on you" will accompany the performance of the gesture. .... The shame fingers gesture will rarely be seen outside of North America, where it has its roots as a gentle rebuke for bad behavior"

from Field Guide to Gestures by Nancy Armstrong and Melissa Wagner

[InternalDialogue]

6. Hmm. Thanks for that.

Although the description of the symbolism is still pretty vague. Sounds like "experts" aren't quite sure, in this case.

And very interesting that it's a mostly North American thing. Maybe there's a clue there.

[Arugula Latte]

7. That's a great name for a band -- "Shame Fingers"