One Reddit user started a thread in the Young Sheldon subreddit titled “Did Dr. Sturgis go to World War II?” in which they suggested that since Dr. John Sturgis was born in 1921, he would be old enough to qualify for the US Army draft, which was introduced in 1940 and lasted until World War II (through Story). “It’s strange to think about it,” they wrote.
In response, some users have given reasons why Sturgis may not have ended up being drafted into the US Army. User Tennis121897, for example, suggested that studying at the university at that time could deprive him of the right to draft. History of conscription in the US Army Selective service system the website confirms that this may have been the case, noting that prior to 1971 active student status was indeed grounds for deferment from conscription.
Meanwhile the user my world wrote that even if Sturgis did join the army, his wits would most likely keep him out of active combat. User HCIBSW confirmed this theory by noting that if Sturgis had been drafted into the military, he would likely have stayed in the US to fulfill an intellectual role in the military.
It is likely then that Sturgis’s academic background influenced his draft status, whether that meant getting him a non-combat job or being barred from military service altogether.