How does Steinbeck present the character of Carlson?

Carlson is a static character who is basically used as a plot vehicle in Steinbeck's Of Mice and Men. He never changes and seems to lack both emotion and sympathy. He is introduced in Chapter Two as a "powerful, big-stomached man." Right away, he is concerned with the dog which belongs to the old swamper Candy. Carlson claims the dog is worthless and "so God damn old he can't hardly walk." He suggests that Slim get Candy to shoot the dog and take one of Slim's puppies. Carlson's main purpose in the story is to act as a representative of a society which has deemed Candy's old dog as no longer useful and thus easily eliminated. Later, Candy will suggest that his fate will be virtually no different than the dog once he can't work anymore. Carlson seems to have no understanding about how much the dog means to Candy and, when Candy balks at shooting the dog himself, readily volunteers, killing the dog with his Luger. The fact that Carlson is little more than an unfeeling laborer is reinforced at the end of the novel when is unable to understand why George is so depressed after the death of Lennie. When Slim reassures George that killing Lennie was the right thing to do and they leave the scene to get a drink, Carlson says, "Now what the hell ya suppose is eatin' them two guys?" Carlson never changes and is just as clueless over George's love for Lennie as he was for Candy's loyalty to his old dog.