Doughty attended Mathematics, Civics and Sciences Charter School in Philadelphia, Pennsylvania. In middle school, he played for the Philly Pride AAU team. Doughty was a two-time first-team all-league selection in high school and led the Mighty Elephants to back-to-back appearances in the league playoffs. He averaged 16.8 points per game as a junior. As a senior, Doughty averaged 24.9 points per game. Doughty originally committed to St. John's out of high school.
