Challenging behaviors such as head banging, aggression, prolonged screaming and meltdowns are not simply “behavioral problems.” They can be important signs that a person with autism is experiencing discomfort in their body. 

Additionally, many nonspeakers and unreliable speakers with autism have rich inner worlds and cognitive abilities that extend far beyond what they can express through speech, movement, and behavior.

Being "locked in"—unable to communicate and utterly misunderstood—is tragic and deeply traumatizing for the child or adult experiencing it.