Doc, as he is referred to by his best friend, Marty McFly, was born in 1920 in Hill Valley, California. A scientist by trade, Doc is a "student of all sciences" and spends much of his time inventing. He usually has a pet dog; in 1955, his dog was named Copernicus, and by 1985, he had a dog named Einstein. Doc's role models are scientists, as evidenced by the names of his dogs and the portraits of Isaac Newton, Benjamin Franklin, Thomas Edison, and Albert Einstein found in his laboratory.
Doc can be absent-minded at times, and despite getting around town due to his repair business he is regarded by many of Hill Valley's townsfolk as strange, eccentric, or crazy. As such, he has few friends. Because of this, Doc is often seen as a loner even though he cares about the people he is close to. However, it is not known when he would have originally met Marty. When Marty goes back in time to 1955, the first meeting is pushed back prior to Marty's birth. Later, after Marty was born and they met again, Doc presumably remembered, but kept this memory secret from the "new" Marty of the positively altered timeline until the "original" Marty returned to the altered 1985.
Doc does not believe in "love at first sight" until he ends up meeting his future wife Clara Clayton in 1885, since he does not see scientifically how such a feeling works.
Doc often works through the night on his inventions and can become obsessed with little things. He will always try to use a big word rather than a small one if one is available--for example, he refers to a dance as a "rhythmic ceremonial ritual". He often tends to enunciate his words with wide-eyed facial expressions and broad gestures. He is also known for his expression of the catch phrase "Great Scott!" He also likes jazz music, Jules Verne and Westerns. Although he may like to gamble, he would never use time travel for that reason. Doc does not usually drink alcoholic beverages, since he has a tendency to pass out after just one drink. Doc is allergic to all synthetic fabrics.