ToM develops automatically for most children without formal instruction. Infants as young as nine months can engage in the beginning stages of ToM. By engaging in joint attention, they seek to point out objects to others to share in the delight. A baby points out objects and watches her parents to see if they smile, thus showing her that they enjoy it too. Failure to point out objects and have a shared experience of pleasure is one of the first indicators of Asperger’s Disorder and suggests a lack of ToM.
By one and a half years, ToM advances to include pretend play, where a baby can use objects in an imaginary fashion instead of solely for the intended purpose. He can use a cardboard box for his train or a stick for his magic wand. The Asperger’s Disorder child’s failure to develop imaginary play is the next indicator that surfaces. However, oftentimes it is only in retrospect that parents will recall that their Asperger’s Disorder child seemed very bound to playing with toys exactly as they were intended to be used and rarely engaged in make-believe.
By the end of the second year, toddlers begin to ask questions about what others are saying, doing, and thinking. While they cannot yet guess what the other person is likely to be thinking, they do understand that others have thoughts and feelings that might be different from theirs. The Asperger’s Disorder child, on the other hand, does not make these observations about others or question what they are doing or why they are doing it.
At age three, toddlers understand that seeing something leads to knowing about it. They grasp the idea that if someone did not see something happen they won’t know it occurred. In contrast, Asperger’s Disorder toddlers assume everyone knows what they know even if the other person was not there to observe it.
By age four, children begin to develop the ability to guess what another person is thinking. They can guess why another person is engaging in a particular behavior and can guess how someone feels. At this level, they have ToM. Asperger’s Disorder children do not even think about what others are thinking, feeling, or doing.
As children grow older, they develop increasing complex abilities in ToM. The Asperger’s Disorder child, however, is seriously delayed and remains stuck at the stage of only considering what he thinks.