The Meaning Behind Crooks' Mannerisms

In part 4 of Of Mice and Men, significant information is revealed about Crooks' personality.  Crooks is very possessive about his room and belongings, so when Lennie attempts to enter his bunkhouse to pet his pup "on raising his eyes [Crooks] stiffened and a scowl came in his face" (68).  Eventually succumbing to Lennie's caring nature, Crooks allows him to stay, but continuously demeans him for being slow, calling him "nuts."  Later, as Lennie explains how George went into town, Crooks teases him, saying "'S'pose George don't come back no mor. S'pose he tok a powder and just ain't coming back...' Crooks face lighted with pleaser in his torture... 'Le's say he wants to come back and can't..  S'pose he gets killed or hurt so he can't come back... They'll take ya to the booby hatch.  They'll tie ya up with a collar, like a dog" (Steinbeck 69-70).  After Lennie becomes angry with Crooks for even considering George could be injured, Crooks becomes intimidated and assures Lennie George would come back.
There are several reasons why Crooks acts so harshly towards Lennie, who only wanted to make friends from the beginning.  One reason is that Crooks, who normally has little social power, recognized Lennie as being mentally disabled and took advantage of him to feel more powerful.  Given the time period and setting of the story, Crooks was likely discriminated against throughout his life due to his skin color.  Lennie is too ignorant to comprehend racial tension, so Crooks could bully him without receiving any backlash.  Another reason he could have bullied Lennie was that he resented society for years of discrimination and abandonment.  Crooks described how he was never allowed to shoot horseshoes or play cards with the white laborers.  He just sat in his separate bunkhouse all day reading and alone with his thoughts, his hatred and resentment towards white people growing everyday they left him alone.  "You got George.  You know he goin' to come back.  S'pose you couldn't go into the bunk house and play rummy 'cause you was black.  How'd you like that? S'pose you had to sit out here an' read books.  Sure you could play horseshoes till it got dark, but then you got to read books.  Books ain't no good.  A guy needs sombody–to be near him" (Steinbeck 71).  So, when Lennie came around acting like Crooks was his friend, Crooks exacted revenge for years of discrimination and abandonment by treating him harshly.  One last reason Crooks could have been so cruel to Lennie is his ineptitude in social situations.  Due to years of abandonment by his coworkers, Crooks may have experienced some social anxiety, which would explain his aggressive interaction with Lennie.
All three of these examples connect to the idea of the predatory nature of man, signifying that even men who have little social power have the primitive desire to dominate their peers without considering the feelings of others.  Although Crooks received much discrimination and harsh language for his differences similar to Lennie, he did not consider Lennie's feelings until AFTER he had upset him.  Crooks would do whatever it took to get on top.