Harris, a Baltimore psychiatrist, is a professor of psychiatry, pediatrics, and mental hygiene and director of developmental neuropsychiatry at the Johns Hopkins School of Medicine. Harris is the principal investigator of an R-01 Research Grant, funded by the National Institute of Child Health and Human Development, to investigate pathways from genes to cognition and complex behavior. He directed the psychiatry program at the Kennedy Krieger Institute in Baltimore for 15 years and is the immediate past president of the Society of Professors of Child and Adolescent Psychiatry.