How do you tell the difference between Asperger's and selective mutism?

Young children who are painfully shy and reluctant to speak are often misdiagnosed, especially when they are observed only in school or a clinician’s office.

Kids with selective mutism (SM) can have totally normal socialization and language skills, and interact typically when they’re at home and in a comfortable place. And even when they are in a situation or location where they cannot speak, they may still have normal interactions and engage with nonverbal cues. (Some kids with SM are also rigid with anxiety, and don’t communicate nonverbally either.) Some are able to speak to other children, but are paralyzed when it comes to talking with adults. Their behavior is often confused with willfulness, but what they are experiencing is an inability to talk, even if they are in distress and in need of help. The key is that the inability is “selective” to certain parts of the child’s life, and stems from anxiety.

On the other hand, kids with Asperger’s are who they are wherever they are, and their way of engaging with the social world is always unusual. (For more on the term Asperger’s and its relationship to autism, see our guide to autism terminology.) Their social difficulties are “pervasive.” Sometimes they do better with kids who are younger than they are because the younger kids will adapt to them, and sometimes they’ll do well with adults because adults can adapt to them. But with their own peers they have a hard time, because kids with Asperger’s have great difficulty with the social navigation that comes pretty naturally to other kids. That’s where these kids often get into trouble — they have a hard time relating to or playing with peers.

So kids with Asperger often don’t get social nuances and the limits of conversation, while kids with SM are socially and emotionally engaged and can pick up nonverbal cues, even if they can’t speak. Kids with Asperger’s are also often very resistant to changes in routine, and respond with tantrums or meltdowns whereas kids with selective mutism internalize their emotions, fears, and needs.

The real defining factor is the presence or absence of social aptitude and emotional reciprocity. It should be noted that though kids with Asperger’s don’t usually have language deficits-they can be very talkative, in fact-many on the autism spectrum do have difficulty communicating verbally, which is partly why new diagnostic criteria will stress social communication deficits and restricted interests.