ROME — Spit in a tube, wait a few weeks, and an algorithm hands you a map of who you might be.Earlier this month genealogy platform MyHeritage said Italians, long the target of inbound roots tourism, are now travelling abroad to trace foreign branches of their own families, with Italian DNA kit sales up 134 percent in five years. Italy Now asked Dr Tracy King, clinical psychologist and independent travel advisor, whether the science supports the itinerary.