Which component of hirschi's conception of the social bond might be considered a "social isolation" variable where someone doesn't care what others think?

The answer is Attachment.

There are four different types of Hirschi's conception of the social bond that binds us together, also called as the bonds of attachment, and they are attachment, commitment, involvement, and belief. 
But what we are after with is the Attachment. This conception asks us "how much do we care what others think?" This attachment that we call depends on the strength of social bonds that hold people to society.