Lennie breaks Curley's hand.
because being a small man
Curley attacks Lennie out of rage and insecurity. He is a small man who feels threatened by Lennie's size and strength, and he targets Lennie in order to assert his dominance over him and prove his own toughness to the other ranch workers. Curley's aggressive behavior reflects his own feelings of inadequacy and a desire to prove himself.
Curley thinks that Lennie is making fun of him through his silence. Lennie is very large and Curley is short. Curley is defensive about his height and dislikes Lennie's silence.
Lennie choked Curley's wife
Curley fought with Lennie because he thought he was superior than everyone else on the ranch since he was the boss's son and since at that time, Lennie was laughing, Curley thought that Lennie was laughing at him. Obviously, as I said before, Curley thought he was better than everyone and he thought that he shouldn't be laughed at by such a low person so he punched Lennie because of his own stupidity and snobbishness.
Curley was in the bunk room beating up Lennie. Curley was looking for his wife and saw Lennie laughing. Curley thought Lennie was laughing at him when he really wasn't. Curley then started to beat up Lennie while George is screaming to Lennie to fight back. Lennie then grabs Curley's fist as he is about to punch him again, and Lennie crushes Curley's fist. The damage to Curley's fist was so bad he was taken to the hospital. Slim forces Curley to say his hand was crushed by a machine. There were hardly any bones left in Curley's hand, and Curley was crying.
He took an arrow to the hand.
At first Lennie doesn't fight back, but then George says get Curley to Lennie so Lennie grabs Curley's fist and breaks his hand and doesn't let go until George starts slapping him.
Curley thinks Lennie's smiling is a sign of agreeing with the rest of the characters in the bunk house when they are all laughing at him. Curley also simply saw this as a chance to attack Lennie because being a small man, he had what the characters call "small man syndrome" and likes to pick on big guys, "Kinda mad at them 'cause they ain't a big guy."
Curley wanted to fight George I think, so he picked on Lennie. He hit Lennie a couple times and then Lennie stopped a punch in mid-air and squeezed Curley fist and brokenit ending his boxing career. Then Lennie Lille Curleys wife and he runs away and George kills him. :)
Physically, the strongest character is probably Lennie, because even though Curley is a boxer and has won trophies, Lennie still easily beats Curley in a fight. Curley is described as "flopping like a fish" when Lennie fights back to defend himself against Curley's unprovoked attack.
Curley beat up Lennie in "Of Mice and Men" out of anger and jealousy. Curley was upset over his wife's flirtatious behavior towards the ranch workers, including Lennie. Being a small man, Curley also took out his frustrations on Lennie to assert his dominance and power over him.