Thinking About Others is Not Child's Play, Massachusetts Institute of Technology (MIT) Study  
8/9/2012 7:48:22 AM

When you try to read other people’s thoughts, or guess why they are behaving a certain way, you employ a skill known as theory of mind. This skill, as measured by false-belief tests, takes time to develop: In children, it doesn’t start appearing until the age of 4 or 5.