Isolated or in the company of strangers, the characters of John Steinbeck's novella Of Mice and Men often feel insecure.
The swamper who is old and disabled, who now only sweeps out the bunkhouses, is worried that he soon will have outlived his usefulness, much like his old dog. This insecurity is indicated in his conversations with the newly-arrived George and Lennie after they enter the bunkhouse. For instance, when he interrupts the conversation of the two men, Candy apologetically tells them,
"I wasn't listenin'. I was jus' standin' in the shade a minute scrathin' my dog. I jus' now finished swampin' out the wash house.....A guy on the ranch don't never listen nor he don't ast no questions."
Later, when he has won some confidence from George, Candy informs the new men about Curley. But, displaying his insecurity, Candy entreats them,
"Don't tell Curley I said none of this. He'd slough me...."
As the only black man on the ranch, Crooks is even more isolated than the others as he if forced to live in the stable. When Lennie ingenuously enters and talks to him there, Crooks is at first unfriendly, and even cruel. However, after recognizing that Lennie is child-like, he confides his insecurities in the man:
"...A guy needs someboy--to be near him...A guy goes nuts if he ain't got nobody...He got nothing to measure by."
Even the flirtatious wife of Curley displays insecurities as she desires the attentions of the "bindle stiffs" to reassure her of her attractiveness and worth: "Think I don't like to talk to somebody ever' once in a while?"
Clearly, Curley's jealousy of his wife represents his insecurity as he has "pants...just crawlin' with ants." Constantly, he comes around the bunkhouse to see where she is and discover what she has been doing.
His insecurity about his size is evident in his building his muscles and becoming a boxer. His unprovoked challenge to Lennie, the largest man in the bunkhouse, also indicates his insecurity as he feels he must establish himself as a 'tough guy.'
After the incident in Weed, George is always anxious about what Lennie may do or say. So, he cautions his friend constantly; in addition, he is anxious about what problems Curley's wife may cause--"she's jail bait"--and he cautions Lennie against angering Curley, the son of the boss.
Mentally challenged Lennie is, of course, dependent upon George. In the first chapter, for example, after George berates him, Lennie face is "anguished." When Crooks threatens Lennie with George's having abandoned him, Lennie becomes greatly upset and worried. Always Lennie is anxious about George's being angry with him and not letting him have rabbits. After he inadvertently kills Curley's wife and he hides in the bushes, Lennie imagines the rabbit telling him,
"Well he's sick of you...He gonna beat hell outa you an' then go away an' leave you."
Lennie put his hands over his ears. "He ain't, I tell ya he ain't." And he cried, "oh! George--George--George!"