NEW YORK — The United Nations is recommending that children as young as five receive mandatory sexual education that would teach even pre-kindergarteners about masturbation and topics like gender violence. The U.N.'s Economic, Social and Cultural Organization (UNESCO) released a 98-page report in June offering a universal lesson plan for kids ranging in age from 5-18, an "informed approach to effective sex, relationships" and HIV education that they say is essential for "all young people."