I had a thought I wanted to bring up yesterday in class, but our time was spent rather quickly.
When I read act three, scene four earlier this week, I was trying to pay careful attention to why this scene is often adapted into a very incestuous exchange between Hamlet and his mother. It's true that there are many accusatory words placed on the queen by Hamlet, but think of how enraged you would be if your mother or father quickly fell in to the arms of another so soon after the death of your other parent. I think he was expressing his disgust at his mother's actions, but nothing more than that.
I had a brief discussion with my mom about the matter, and we came to an agreement that the incestuous adaptations of this scene came about at a time when there was a trend to read everything in an Oedipal light. Just like how many t.v. shows, plays, movies, etc., now have a homosexual read into it, there was also a time not too long ago when the public looked into incestuous relationships as the default psychological background.
I did think of another explanation as to why these adaptations of incest between Hamlet and the queen occur, and I think it comes with modernity and a better understanding of the psychology behind men who are rapist. The heated discussion between Hamlet and his mother could be seen as a need for Hamlet to prove his power, therefore forcing himself upon his mother who he sees as being "whorish" for so quickly marrying his uncle.
Anyway, I guess in order to look at the psychology behind different adaptations of Shakespeare's plays, we need to look at the psychology of the times in which the adaptations were performed.