I am officially amazed at how many similarities are shared by the dialects of Central Pennsylvania and the entire American South.
8. Use of the word about to mean very. For example “You’re about dumb.” means “You’re very stupid.” Sometimes the word half is added for extra emphasis. Therefore, “You’re are about half dumb.” means “You’re extremely stupid.” The term about is not a true substitution for very but rather it is understood to be an intended understatement on the part of the speaker. The about-half dumb construction has evolved into the otherwise incomprehensible Central Pennsylvania insult “You’re about half!”