First, there are persistent difficulties in communicating with others and in social interactions: difficulties in reaching out to others, difficulties in sharing emotions and affects, and even an inability to initiate or maintain social interactions. There are also difficulties in non-verbal communication behaviors: abnormalities in eye contact, poor use of common gestures or facial expressions. It is possible to have difficulty understanding and/or predicting the behaviours and intentions of others due to varying degrees of difficulty in grasping the implicit and abstract.