Child psychology

An interesting example of child psychology: Elise knows she is two years older than Vincent. "I am four and he is two. When I am ten, he is eight. When I am thirtytwo, he is thirty," and so on. We were impressed and played the game for a while, calling out numbers between four and one hundred. However, when we changed the question into: when Vincent is four, how old will you be? she would not know the answer, no matter the ages we tried... Answering the question requires taking the perspective of the other and when you are four, this is virtually impossible.(It obviously was not so much math what she was doing; when we are doing math, she is able to answer the question!)