Proband means a testee, a medical term used for examinations into genetic material. In examinations into twins the first born is indicated as a, the second born as b.
The quote on the invitation comes out of a book were twins are telling about their experiences with the horrible experiments of Mengele in the 2nd world war. Although you are immediately shocked by the terrible stories, we did choose this quote because we want to make clear that there is a prejudice in judging people which is socially incorrect. It is about the frustration to be always compared with each other, who is the better, the more beautiful, the funnier and above all the more popular of the two individuals who should have the same qualities from the start. The fact that we ourselves are twins has, of course, a lot to do with this situation and we took this as a starting point in the examinations into the two girls; the questions in the case report are based upon the differences between ourselves, there for it is a search for the reasons why we have the appearance we have and the feelings of guilt that come with it. As a twin you almost unconsciously draw attention, people are often examining you for differences without realizing it (only when you look them straight in their eyes they become aware)That is why we hate the image of the twin as harmonious couple, being photographed next to each other.
The opening performance was meant to turn this irritation around: the obligation to choose for one individual and the inability to compare the two irritates the public and apart from that the feeling will rise of having chosen for the ‘wrong’ one. The fact that they wonder which side is the most interesting one will force them to talk to other people. In the end the audience is examined as well ; the way they behaved is visible in the mess they left behind.
Although it seems that with a case report you make an attempt to lay down an identity, in reality it is more an examination of environmental circumstances which determines behaviour, with the twins as well as the audience