When they are around 2 or 3 years old, children begin to recognize aspects of other people that cannot be seen (i.e.: desires, feelings, and thoughts). However, it takes a few years before children learn that other people’s feelings, desires, and beliefs can be different from their own, and how to deal with these differences. This emerging ability is known as 'Theory of Mind'.
Although Theory of Mind has been studied intensely in infants and preschool children, surprisingly little is known about how school-aged children's Theory of Mind continues to change as they grow and develop.