One defining symptom of Asperger’s and autism is a difficulty in reading social signals, body language and facial expressions. But, lots of people struggle with this, not just those on the autism spectrum. Although for neurotypicals, reading others tends to be instinctive, everyone, autistic or neurotypical, can learn to pay attention and improve their skills.
There’s a fun self test on the BBC website where you can practice identifying real and fake smiles. The test has videos of 20 people smiling which you can analyze. During the test you can only watch the videos once, but if you want to study them repeatedly, you can review them after you get your results.