“Do illiterate people get the full effect of alphabet soup?”

“Do illiterate people get the full effect of alphabet soup?” is a joke that has been credited to comedian John Mendoza since at least 1988. Alphabet soup contains letter-shaped pasta and is often served to children. Reading skills are not required to consume the soup.
 
 
Google Books
Hispanic Link Weekly Report
Volume 6
1988
Pg. ?:
TODAY’S PROVOCATIVE THOUGHT: (offered by comedian John Mendoza on a September HBO comedy special): “Do illiterate people get the full effect of alphabet soup?”
 
31 January 1992, Buffalo (NY) News, “Noteworthy”:
With a sardonic delivery that makes him sound like a fatigued New York bookie announcing a snail race, Mendoza has been known to wonder aloud, “What if there were no hypothetical questions?” and “Do illiterate people get the full effect of alphabet soup?”
 
Google News Archive
1 January 2004, The New Era (Parker, SD), “Points To Ponder” by Jim Hensley, pg. 2, col. 2:
Do illiterate people get the full effect of alphabet soup?
 
Google Books
The World’s Greatest Email
By Sue Shifrin-Cassidy
Bloomington, IN: AuthorHouse
2007
Pg. 55:
Do illiterate people get the full effect of Alphabet Soup?
   
Houston (TX) Chronicle
Hoffman: Read George Carlin’s books for comedic brilliance
By Ken Hoffman | June 23, 2008
Do illiterate people get the full effect of alphabet soup?
 
Google Books
The 2,548 Wittiest Things Anybody Ever Said
By Robert Byrne
New York, NY: Touchstone (Simon and Schuster)
2012
1,069
Do illiterate people get the full effect of alphabet soup? —John Mendoza