Extraordinary People: Understanding Savant Syndrome is a book authored by Darold A. Treffert.
The book was first published in 1887 by Dr. J. Langdon Down in 1887. It was the first book of its kind to present many cases of Autistic savant, and "documents the spectacular abilities of these remarkable people, and describes as well the love, determination, and dedication of their equally remarkable families, teachers and caregivers"  while the subsequent edition records observations and comments gathered for more than forty years by Dr. Treffert. The book is divided into three parts, namely, 'Genius Among Us', 'Portraits', and 'Genius Within Us'; and is preceded by a section recording Acknowledgments, an Introduction, a Prolouge, and a separate section named Savant Syndrome:Defining the Condition. A 15-page Index  completes the book.
Part one of the book ('Genius Among Us') has seven chapters:
- The Genius of Erlswood Asylam and other early savants;
- Music: Language for an Endless Infancy;
- If this is June 6th, It should be Friday:
- The Calendar Calculation;
- The Brilliant and the Backward: The Lightening Calculators;
- "An Exaltation of Memory: The Mnemonists;
- The Cats' Raphael and Other "Rara Avis"; and
- From Mr. A to Mr. Z: Other Savant Skills.
The part two ('Portraits') has three chapters:
- Ellen; and
The part three ('Genius Within Us') has seven chapters:
- Explaining the Inexplicable;
- "Great Vigour of Money" - in the Savant and in the rest of us;
- New Savants and the New Findings;
- How Do They Do it?
- And What of the Future;
- A Smoother Peeble; and
- Rain man, The Movie/ Rain Man, Real Life.