Aaron is the central character of the play. He appears to have suffered some sort of trauma which has led to him becoming obsessed with the idea of simultaneous events in close proximity. He introduces all the other characters which he claims do not know each other, but all attend one school. He introduces them because they all have separate problems which do not inter-relate, except by proximity. At the end of the play it is revealed that his sister was raped in the room next to him, while he was playing a video game, oblivious to what was going on in the next room.
In the play, Aaron is a boy of around 18. He lives with his two parents, Donna and Brian, his little sister Julia and his big sister Adrian. Little is explained about his life, so it is likely that he is just a normal teenager. He is very intelligent as he has a good understanding about the philosophy of simultaneity and has a wide vocabulary, using words such as 'concurrent' and 'arbitrary'.
Aaron is very charismatic as he has the confidence to address an audience directly. However, it is questionable whether Aaron is actually breaking the fourth wall and is interacting with the real audience, or whether he is talking to his own imaginary audience, in his own world where they will applaud, laugh and cry when he wants them to. I think it is the latter for three reasons. The first is because of the naturalistic ending sequence, which completely contrasts the style of the rest of the piece. The second is because I believe the play is all about Aaron trying to regain control. He has realised that he was utterly powerless to help his sister, so he has created his own characters to control and his own audience to hear him out. He initially believes that when he says what happened, he will be more able to protect his sister in the future. However, he soon realises that he can't talk about what happened because he feels too guilty.
The third reason is because Aaron is an introvert. An introvert is someone who more often than not, directs thoughts and emotions inwards. They are less likely to speak their mind and more likely to repress emotions. The reason I think Aaron is an introvert is that during the ending sequence, Adrian has to work very hard to get Aaron to tell the truth about how he's feeling. But when Aaron is on his own with his thoughts, he couldn't be any more expressive. This is why I think Aaron could never break the fourth wall and is more likely performing in front of his ideal, supportive and imaginary audience.
Aaron also has an internal locus of control. Someone with an internal locus of control is someone who, more often than not, believes that their actions solely affect their own lives, as opposed to someone with an external locus of control who, more often than not, believes that other people and forces beyond their control solely affect their own lives. I believe Aaron has an internal locus of control because he blames himself for the rape of his sister. There is absolutely nothing he could have done to prevent it, as he was not even aware of it, but he still believes that he is to blame. Never, throughout the whole play, does he blame the rapist.