You could include some of the following points in your essay:
You might argue that he is heartless and shows little regard for Candy’s distress in allowing the killing of Candy’s dog.
He is unsentimental about the pups, showing his pragmatismThinking of or dealing with problems in a sensible and practical way., “I would have had to drowned most of ‘em”.
He is no better than the other ranch workers, he frequents Susy’s place.
He does nothing about how Crooks is treated.
He seems to encourage Curley’s wife’s flirtation by calling her “good looking”.