But when the in-group is defined as "is blind"?? I'm not just talking about programmers in this context, or any other cross-section wherein there's some sort of shared vocabulary and context other than the disability itself. I don't think it's been studied, but I've noticed, my parents have noticed, in general enough people around me have noticed it over the years that I'm convinced the effect is real. Is whatever mechanism you're referring to typically general enough that the group can be defined this broadly and still have it happen?