Psychology
My subsidiary subject is psychology. I chose this subject in order to provide some other views of the world to my brain except those of mathematics and computer science.

Still today it is quite happy with this decision... Psychology is a science which is not as old as other sciences like mathematics. This branch was founded at the end of the last (well, the one before last soon...) century by Wilhelm Wundt.

In contrast to the medicin science, psychology deals with the function and the action of the human brain. But you don't look at the physiological aspects like bloodpressure etc. but how does the human sense.

I currently work on a rather interesting practical course which deals with the question which property of a letter leads to the impression that a word looks balanced or not.