Edited sentence: "Schizoid personality disorder (SPD) is a personality disorder characterized by a lack of interest in social relationships, a tendency towards a solitary lifestyle, secretiveness, emotional coldness, and apathy.Affected individuals may also demonstrate a simultaneous rich, elaborate, and exclusively internal fantasy world[1], although this is often more suggestive of schizotypal personality disorder.Even though subject reveals OCD type behaviour, this might be due to his extremely dissociative state with his own body.Sheldon's anxious, nervous personality and strong feelings are very different to the blunted emotion and apathy seen in schizoids, making it unlikely he has this condition.Some viewers consider this the underlying cause for Sheldon Cooper's behaviour