What is the significance about the motif of "hands" as it runs through Of Mice and Men?
The leitmotif of hands runs throughout Of Mice and Men because it is supposed to distinguish man from animal. Ironically, it doesn't. Just as Curley's hand is crushed, so too is George and Lennie's American dream.
First, Lennie is described as having huge paws, like a bear, when he laps up the water in Chapter 1. This shows the use of anthropomorphism in the novel, as Steinbeck substitutes human qualities with animal description. In this time of economic dogfighting, men were reduced to animals in their pursuit of work and equality.
Both George and Lennie are traveling hands: "ranch hands." It is a profession in which they give an employer a helping hand for a season. The owner should seem grateful for this, but he is not. He suspects George of stealing from Lennie (something else done with a hand, by the way.)
Curley is a boxer: he uses his hands to pummel men. But he keeps his hand in a glove filled with vaseline. This shows the gender differences of the hand: it is used as a weapon and a sexual instrument. This rather sexist depiction of men suggests they were supposed to use their hands violently in public and tenderly in private.
Carlson uses his hand to fire a gun to kill Candy's dog, and George uses his hand to fire a gun to kill Lennie before Curley can do the same. The gun is an extension of the hand.
Lennie crushes Curley's hand. This is a kind of revenge by the worker against the privileged non-worker. Lennie's bear claws crush the dreams of Curley (to be a fighter and a lover) since Curley first tried to crush Lennie's dream. In the end, both dreams are crushed and both men resort to and become victims of animalistic violence.