In 1975, Kingsley made his television debut on Sesame Street at 15 months old and appeared in 55 episodes.
His mother is a writer for Sesame Street and his father was a painting contractor.
[5] Kingsley graduated from Lakeland High School in 1994, and passed all six special education Regents Competency Tests.
In June 1997, he graduated from Maplebrook School, a post-secondary school for students with learning disabilities.
[6] In 1994, Harcourt Brace published Count Us In: Growing Up with Down Syndrome, a book Kingsley co-wrote with friend Mitchell Levitz about their experiences with Down syndrome.