Compare Tom Buchanan and George Wilson, especially in terms of their attitudes toward women, and their ways of showing violence.
Both Tom and George are violent, Tom when he hits Myrtle, has a scuffle with Gatsby, and in the way that he approaches people he thinks are beneath him or that have wronged him in some way. He apparently was less like this until after he finished school where the hardness in him became more apparent and he began actively ruining people when possible.
George also acts on violent impulses and kills someone out of the rage that he feels for being picked on by everyone including his wife. He feels a certain futility in his life based on his work, his location in the wasteland, and the fact that he still has to depend on the very people who've ruined him financially and emotionally by having an affair with his wife.
Both George and Tom are relatively one-dimensional and serve to highlight characteristics like a certain thoughtlessness and cruelty.
Tom and George are more alike than they are different. The biggest difference between the two of them is money. Tom is very wealthy and uses his money as a weapon. He wants the best, and is going to have the best, no matter what. He wants everyone to look at him with envy because of his money and power. George, on the other hand, is not wealthy. He is a working class guy. He doesn't have the financial resources that Tom has. George's wife, Myrtle, wants more money and more social standing. She belittles George because of this and ends up in an affair with Tom, hoping he is the way to getting what she wants.
The two men are very similar. They are both very violent men. Tom hits Myrtle, so we see that he has anger issues. Tom uses his standing in society to bully people into doing things the way he wants them done. He thinks he can have whatever he wants, without having to pay any consequences. George, on the other hand, is also a violent man, but his temper is harder to control. He is a loose cannon. George is sick of people treating him the way they do, so he loses control of his anger, with tragic consequences. George has to pay for his violent ways, while Tom is able to just walk away from his.
Both of these men are more alike than they would like to think. Their anger and tempers control and run their lives. Only Tom, with his wealth and power, is able to get away with acting like this, while George has to pay fully for his actions.
On the face of it, Tom and George are pretty different. Tom is wealthy, and George is poor. Tom is a bully; George is bullied. Tom never works; George works all the time.
The men are connected by Myrtle, George's wife and Tom's lover. Myrtle moves both Tom and George to violence. Tom, caught by his need to assert dominance over both his wife, Daisy, and Myrtle, brutally suppresses Myrtle in Chapter two:
“Some time toward midnight Tom Buchanan and Mrs. Wilson stood face to face discussing, in impassioned voices, whether Mrs. Wilson had any right to mention Daisy’s name.
“Daisy! Daisy! Daisy!” shouted Mrs. Wilson. “I’ll say it whenever I want to! Daisy! Dai—”
Making a short deft movement, Tom Buchanan broke her nose with his open hand.
Then there were bloody towels upon the bath-room floor, and women’s voices scolding, and high over the confusion a long broken wail of pain.”
There is a kind of sordid, cheap cruelty in this scene that belies Tom's wealth and power. Tom hits Myrtle to make her "behave."
Wilson, on the other hand, is moved to violence by Myrtle indirectly, after she is run over by Gatsby's car. After Tom leads him to believe that Gatsby is responsible for her death, he goes to Gatsby's house, shoots Gatsby, then turns the gun on himself. He is trying to avenge Myrtle's death, I suppose, but ultimately he has been tricked by Tom into doing what Tom himself would never do. Tom's entitlement, his "right" to own everyone and everything around him, is perhaps matched only by George's lack of will and gullibility. Nevertheless, they are both motivated by a desire to control a woman.