In the words of George Costanza: "I was in the pool! I WAS IN THE POOL!" OF COURSE polar bear genitals are shrinking. It's freezing up there! Give the poor bears the benefit of the doubt!
As the exchange went on Seinfeld:
Jerry, George: Elaine!
Jerry: Do women know about shrinkage?
Elaine: What do you mean, like laundry?
Jerry: No, like when a man goes swimming; afterwards.
Elaine: It shrinks?
Jerry: Like a frightened turtle!
Elaine: Why does it shrink?
George: It just does.
Elaine: I don't know how you guys walk around with those things.