Although the Dunce cap was used as a disciplinary thing, it later became a fashion statement that spread all over USA/Americana.

A random quote by a random Autobot: Edit

"Attack those Dunce-headed Decepticreeps!"
Here, the term was used to describe Seekers, particularly Coneheads.

Another random quote: Edit

"Don't you dare call my Daughter a dunce-bot!"
~ Jazzimus Prime talking about Airazor, and someone insulting her.