Child Testing

For my testing I did the experiments on my nephew. He his five, turning six in March. I did three of the experiments that you showed us in class last Wednesday and he failed all three tests.
First I placed two glasses of water that were the same size with the same amount of water in them. I asked him which one had more water. He told me they were the same. He then watched me as I dumped one of the glasses of water into a taller, thinner glass. I asked him the same question and he said the taller glass had more.
For my second experiment I placed to pencils parallel pointing towards him. I asked him which pencil appeared to be longer. Once again he told me they were equal. I then moved one pencil a couple of inches towards him and repeated the question. He told me the one closer to him was longer.
For my third and final experiment I placed two equal round balls of clay in front of him and asked him which one had more clay. He told me they were the same. I then smashed one of the balls in front of him and once again asked him which one had more clay. He told me the smashed ball contained more clay. I asked him why and he told me because it looked wider and fatter.
I was not surprised with his reasoning because he does fall into his age group although I would have expected him to find the round ball bigger than the flat ball. It was very normal to jump to the conclusions that he did but I still find it very interesting that a child can watch you change the shape and automatically assume you have added or removed matter.