Similar to a loner, but on a larger scale. They appear to be detached and emotionless, but they are still people. They have little regard for social norms. For more information, see loner
*note: Schizoids are NOT schizophrenic. The similarity in name is because they basically mean 'split from society' and 'split up mind' respectively.
Jack is such a schizoid, I think he's some robot or something.