In Rand’s study…There were more than two hundred grocer’s cartons, each divided into sections and filled to the brim with colored stones Rand had collected and sorted.

This is from Anne C. Heller’s biography of Ayn Rand. Based on reading Tyler Cowen’s Create Your Own Economy, I would view this stone-sorting behavior as a symptom of someone who was somewhere on the autistic spectrum. Heller does not mention autism or Aspergers’, but there is much in her biography of Rand to lead one to speculate that Rand was a high-functioning individual with that sort of disorder.