Being able to support a kid through income, having basic intelligence. Just means a child should have for success. Of course, many people would have these, so you'd have to do it through a lottery (Ie: "You passed the tests! Now you'll have to wait several months to find out if you are the lucky recipient of a liscense!"). Obviously, not going to work in anything short of an "ideal" (there aren't enough quotation marks for this) world for reasons you and others described.