https://psychcentral.com/disorders/aspergers-disorder-symptoms/
Asperger’s disorder is a syndrome that typically appears first in childhood, and is primarily characterized by a person’s difficulty in everyday social interactions with others. For instance, a person with Asperger’s may engage in long-winded, one-sided conversations without noticing or caring about the listener’s interest. They also often lack usual nonverbal communication skills, such as engaging in eye contact with others during conversation, or failing to react and empathize with other people’s stories and conversation. This may make them seem insensitive, although that is rarely the case. They may have a hard time “reading” other people or understanding humor.
Adults, too, may have Asperger’s, as often the disorder is not properly diagnosed in childhood. Asperger’s is considered the mildest, least severe form of autism. The following five criteria primarily characterize Asperger’s disorder.
1. A significant, ongoing impairment in social interactions with others, as demonstrated by at least two of the following symptoms:
Significant difficulty in the use of multiple nonverbal behaviors such as the lack of eye contact, few facial expressions, awkward or clumsy body postures and gestures
Failure to develop friendships with other children of the same age
Lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest to other people)
Failure to express appropriate and corresponding social or emotional reactions, such as when conversing or playing with others. For example, a child who shows little or no reaction, feelings, or empathy to another child talking with them.
2. Restricted and repetitive patterns of behavior, interests, and activities, as shown by at least one of the following symptoms:
A significant and encompassing preoccupation or obsession with one or two restricted topics, that is abnormal either in intensity, subject or focus (such as baseball statistics or the weather)
Seemingly inflexible adherence to specific routines or rituals that serve little purpose
Repetitive motor mannerisms. For example, hand or finger flapping or twisting, or complex whole-body movements.
A persistent preoccupation with parts of objects
3. The set of symptoms causes significant impairment in social, occupational, or other important areas of functioning.