I don't know if I will be able to answer your question completely, but I'll take a stab at it.
I did some research and found everything from children questioning these statements to references of Marlon Brando playing Stanley in A Streetcar Named Desire.
What does seem to be consistent is the type of clothing. The question about the tank top seems to have evolved from a student in a private school wanting to know why the school would object to it. There is a very fine line between tank tops and spaghetti strap shirts.
However, making the jump from that phrase to a wife beater seems to have proved the most difficult in the research. Some of the discussions I read seem to think it might be racially motivated. These racial indications stem anywhere from African-American to Italian to the back hills of the United States.
Since I really couldn't find a definitive answer, I would be guessing when I say another definition of the garment you are asking about would be a "muscle shirt" because the T-shirt in question exposes all the muscles a person has in their upper arms as well as the chest and addomen muscles can sometimes be seen. A man beating his wife would, I would presume, use his muscles.
That would be my guess, but I am really not sure.
Merry Meet and Merry Bide
Cheryl
