A prevalent theme of Steinbeck's "Of Mice and Men" is the alienation of men, particularly in the Depression era when so many had to abandon their homes and become itinerant workers in efforts to seek employment. This motif of separation from the bonds of love and fraternity is exemplified in several of the characters, and Curly is one of them.
In contrast to George and Lennie, two friends who move around together, Curly has a partner, a wife, with whom he lives. However, she is a cheap woman who merely married for some security. Often she comes by the other men under the pretext of "looking for Curley":
She put her hands behind her back and leaned against the door frame so that her body was thrown forward. 'You're the new fellas that just come, ain't ya' [she says to George]....She turned her head. 'Hi, Slim,' she said.
Slim's voice came through the door. 'Hi, Good-lookin''
Later, when Curly seeks his wife in the bunkhouse, Slim turns angrily upon him,
'Well, you been askin' me too often. gettin' God damn sick of it. If you can't look after your own God damn wife, what you expect me to do about it? You lay offa me.'
Thus, rather than providing Curly with love and companionship, she becomes a source of anxiety to him, causing him to come into conflict with the other men, conflicts he seeks to resolve by confronting Lennie. But, instead of asserting his dominance, Curly is hurt when, with animal strength, Lennie crushes his hand.
The son of the boss, Curley is not displaced and alienated from society as the other men are. However, in his personal life, Curley has no friends since he has estranged himself from the men in the bunkhouse because of his jealousy for his wife. George reflects upon the trouble that women can be by recalling to Lennie that their friend Andy Cushman is in San Quentin prison "on account of a tart." Because of his "tart" wife, Curley is outside the fraternity of the men, a brotherhood that Steinbeck felt was a necessity to the happiness of men. For, it is the dream of community and home that Lennie and George that keeps them from feeling so much their terrible aloneness.