The uniformity and ease with which our discussion group discriminated between the feeling one gets around someone with a physical injury or disease as apposed to mental illness was thought provoking in contrast with the disparate views on why that is. Is it the breach of the social contract through abnormal behavior? Is it the unpredictable behavior that makes us uncomfortable? Is it fear of being attacked? Is it caused by not knowing why someone is acting a certain way?
At first I thought it might be fear of violent behavior, but then I watched Ted Bundy and he's so "normal" it's hard to imagine being scared if you didn't know who he was if you met him.
Then I thought it might be the lack of cues about what was going on inside, especially through flat affect, but Jeffery Dahlmer is only slightly more creepy than Bundy, even when speaking on the subject of his murders.
I don't think it's simply the breach of the social contract, because my girlfriend thinks this guy's hot. While people do stare I would hazard to guess it is more because they don't know why than that it is happening. I would suspect that if people were told it was Tourette's that they would ignore it pretty quickly.
My personal feeling is that this uncomfortable feeling is caused by the unpredictable behavior of certain mental illnesses combined with situation. A disheveled, dirty man speaking to himself on a bus would likely cause more people to feel discomfort than an attractive, clean woman doing the same thing. Likewise, an "average Joe" talking to himself and acting otherwise abnormal because of mental illness would cause more disquiet than would the same person exhibiting the same behaviors but known to you to be doing so because a brain tumor was pressing particular areas responsible for the behavior. It would be interesting to do some naturalistic observation followed up by surveys to start to parse the source of these often visceral feelings of disquiet. Do you feel differently about any of my examples? How?