Well, in the Crucible, a predominant theme is the fact that Danforth and the court create a situation where it is expected that all individuals will choose to belong in order to survive. I would see that - Danforth's authoritative place in society and his unshakeable 'justice' - as a key factor in his view of belonging as a black and white matter - "either with this court or you must be against it". He symbolises a circumstance that in turn influences individual ideas of belonging.
Proctor, for example, has changing perceptions of belonging. At first, he along with Giles Corey refuses to conform. This is a natural trait of his (there's a quote in the big stage direction at his introduction about him being against the moral fashion of his time). When he is faced with the ultimatum between conforming and death, he breaks down and chooses to belong. Yet at the same time, his pride is so integral to his sense of identity that he can't give up his "name". The person that he is - formed by his experiences, I guess - heavily influences his ability to follow the crowd, even if doing so would save his life.
You could also talk about Mary Warren, whose timid personality makes it easy for her to be swayed to belong to one group or another. On the experience side, she is used to following a leader around, and is well acquainted with being punished when she disobeys. If I remember right, Abigail threatened the girls that night of witchcraft. Proctor also gets her to admit the truth (not remembering this too clearly) by being somewhat forceful - Danforth or someone even asks if Mary changed her testimony because she was threatened. Later, Mary goes back to Abigail and the girls when they put on a victimised act to pressure her into saying that Proctor had indeed threatened her to tell a 'lie' (I think)
Your thesis would be to agree with the question by saying that the experiences of individuals and their place in society heavily influences their decisions about belonging. You'd expand it a little further, but that's the basic gist. I have the tendency to structure most essays around characters, so I would talk about Danforth, Proctor and Mary, and maybe another suitable character - someone in a situation not entirely similar to the above, for diversity?
I've let go of most HSC content after exams, so pardon me if some facts are wrong XD This is only how I would approach the question, and it's how I mostly structured my prepared essay.
