As a young child, Shaun was raised alongside his younger brother Steve by their mother and father. He attended school, where he was bullied by the other children.
Little is known about Shaun's mother (though he mentions she made good pancakes). His father's method of child-rearing eventually turned abusive, ultimately resulting in him killing Shaun's rabbit when his son was fourteen. Shaun and his brother ran to the nearest "doctor place" (as Steve called it), where they met Aaron Glassman for the first time. It was during this time that Steve promised Shaun they would never go back to their parents. He also gifted Shaun a small toy scalpel, which would be treasured for years to come.
The two ran away together and lived in an abandoned bus together, until Steve's accidental death while playing in an old building with a group of other children. Shaun was picked up by a police officer, who tried to take him back to his parents; at this point, he fell apart in the back of the squad car, screaming and crying about Steve's promise to him. Ultimately, Glassman took Shaun in, and raised him like a son.
He lived independently in Casper, Wyoming for some time (though both Glassman and Shaun note that his neighbors provided much-needed help). With Glassman, he managed to develop his skills to be a doctor and to later control his emotions and remain calm in tough situations. Later, he moved to San Jose to begin his residency at St. Bonaventure.
Shaun has "almost perfect recall," extraordinary and genius-level intellect, and the excellent analytical abilities that allow him to make highly accurate diagnoses. He dislikes direct questions and confrontation. He is highly perceptive and often bluntly voices these perceptions, such as noting that his superior, Dr. Neil Melendez, was "arrogant" on the first day that they met. During hospital scenes, Shaun's thought process is frequently captured in an overlay for viewers, demonstrating his eidetic memory. This implies he is a highly visual learner.
His autism is depicted as obvious to many of the people he interacts with. He displays several traits of his condition, including heightened sensory sensitivity, abnormal inflection when speaking, lack of interest in eye contact, and heavy reliance on routine. Additionally, he becomes fixated on certain objects at times, most notably the toy scalpel Steve gifted him. He insists on eating the same thing for breakfast every day: yoghurt and a green apple except for Mondays when he has breakfast with Dr. Glassman at the hospital. He eats chocolate chip pancakes with a glass of milk.
Despite Shaun's troubled childhood, he maintains a generally positive outlook on life, choosing to pursue medicine in the hopes of improving the lives of others. However, he is wary of forming deeper relationships with people after the death of his brother and his rabbit. Shaun is revealed to have a great degree of proficiency, if not fluency, in Spanish. He also mentions an interest in football in at least one episode. Among the things Shaun dislikes are pickles, coffee, and direct questions. He has an aversion to physical touch unless he is the one to initiate it. He is shown as being fond of cats.
|"Burnt Food"||"Mount Rushmore"||"Oliver"||"Pipes"||"Point Three Percent"||"Not Fake"|
|"22 Steps"||"Apple"||"Intangibles"||"Sacrifice"||"Islands: Part One"||"Islands: Part Two"|