“He’s so dumb, he stayed up all night studying for a urine test”

It’s an old joke that a person is so dumb, “he/she stayed up all night studying for a urine test.” The joke has been cited in print since at least 1968, when it was a Polish joke. The joke has also been told as a “dumb blonde” joke.
 
The joke has been frequently told about a school’s athletes, who sometimes do have to take urine exams. The joke was a Texas A&M Aggies joke in 1977, and has been told about football players at the University of Georgia and the University of Miami.
 
     
Google Booke
Folklore Archives of the World:
A Preliminary Guide, Issues 1-5
1968
Pg. 27:
Urine Test (Bauehman J2259X(pp)) The Polack stayed up all night studying for it.
 
21 July 1977, Cullman (AL) Times, “Footnotes About People: Aggie Jokes” by Don Sneed, pg. 4A, col. 6:
Or, the Aggie who stayed up all night studying for his urine test?
   
Google Groups: rec.sport.football.college
Texas Tech vs. Texas A&M
Laura Mansfield
10/2/92
(...)
Did you hear about the Texas Tech cheerleader who stayed up all night studying for her urine test?
 
Google News Archive
29 September 1999, The Southeast Missourian (Cape Girardeau, MO), pg. 9B, col. 2:
You have to stay up all night studying for your Urine Test. —Lloyd Young
 
Google Groups: rec.sport.football.college
I am officially old, old school
Scott
2/22/01
(...)
Ha, that’s funny…Did you hear about the Aggie who stayed up all night studying for his urine exam??
     
Google Books
Get ‘Em Laughing:
Public Speaking Humor, Quotes and Illustrations
By E. Gene Davis
Victoria, BC: Trafford Publishing
2007
Pg. 165:
Did you hear about the Georgia football player who stayed up all night studying for his urine test?
 
Twitter
money=power
‏@whamytami
Did you hear about the University of Miami fullback who stayed up all night studying for his urine test?
11:58 AM - 1 Dec 2015