People with autism -- partly because of the problems they have with communication -- have difficulty developing friendships and playing cooperatively with others. Often, children with autism don't pick up on social cues, and are less likely to spontaneously seek social connections.
Despite the challenges children with autism face regarding social interaction, they still have the desire to interact. Children with autism may just need direct instruction to learn what others pick up by mere observation.
Although there is no single feature that all people with Asperger syndrome share, difficulties with social behavior are nearly universal and are one of the most important defining criteria. Aspies struggle to notice the subtexts of social interaction, and may lack the ability to communicate their own emotional state, resulting in well-meaning remarks that may offend others, or uncertainty about what is acceptable.
The unwritten rules of social behavior that mystify so many with AS have been called the "hidden curriculum".  Aspies must learn these social skills intellectually through seemingly contrived, math-like logic rather than intuitively through normal emotional interaction. 
Neurotypicals are able to gather information about other people's feelings based on clues from facial expression and body language, but Aspies have more difficulty noticing and interpreting this information. For example, an Aspie might not notice that her friend is annoyed, might see the annoyed expression but not realize that is important, or might recognize that her friend is annoyed but not realize that it was because she tracked dirt into her room.
Aspies struggle with putting themselves in other people's shoes. As one Aspie put it, "The brain is an incredibly complex instrument. How could I begin to fathom the intricacies of another person's mind?" In this respect, people with AS are impaired; this is sometimes called mind-blindness, or a lack of theory of mind.   This makes it difficult for them to understand what to expect of people, or what people expect of them. They make social mistakes quite often compared to neurotypicals.
Aspies also might have trouble showing empathy with other people, and may be unfairly seen as egotistical, selfish or uncaring. In fact, they often care deeply about other people's feelings, but simply don't understand what is socially acceptable and what is not. People with AS are usually surprised, upset, and remorseful when told that their actions are hurtful or inappropriate.
Failing to show affection — or failing to do so in conventional ways — does not necessarily mean that people with AS do not feel affection. Understanding this can lead partners or care-givers to feel less rejected and to be more understanding.
- Myles, Brenda Smith; Trautman, Melissa; and Schelvan, Ronda (2004). The Hidden Curriculum: practical solutions for understanding unstated rules in social situations. Shawnee Mission, Kansas: Autism Asperger Publishing Co., 2004. ISBN 1-931282-60-9.
- Levanthal-Belfer, Laurie and Coe, Cassandra (2004). Asperger Syndrome in Young Children: A Developmental Approach for Parents and Professionals. London: Jessica Kingsley Publishers, p. 161. ISBN 1-84310-748-1
- Romanowski, Patricia; Kirby, Barbara L. The Oasis Guide to Asperger Syndrome
- Baker, Linda and Welkowitz, Lawrence A.; eds. (2005). Asperger’s Syndrome: Intervening in Clinics, Schools, and Communities - People with Asperger's Syndrome Can Lead Productive Lives. Lawrence Erlbaum Associates, Inc.