In Anderson's sophomore year, Rainier Beach finished as the state's runners-up and as a junior, he gathered all-conference and all-city accolades.
In his final high school season, he averaged 19 points, 9 rebounds, and 7 assists, leading his team to a fourth-place finish at states with a 23–7 record.
Anderson also played Amateur Athletic Union (AAU) basketball for the Friends of Hoop in the summer of 2005 with Isaiah Thomas of the Boston Celtics and Spencer Hawes, averaging 12 points, 4 rebounds, and 3 assists.
He is the son of Carla and Paul Anderson, and has four sisters, Taylor, Erin, Deborah and Kela, and a brother, Austin.
Anderson is a musician in his spare time, as he sings, writes, produces and also plays six musical instruments (drums, bass, guitar, sax, piano and keyboards).