That is stupid because it is unnecessary. They already know our age from our case sensitive information that we fill either in our ID or whatever. There are so many factors, humans are so different, their mental maturity level so divided it is impossible to tell someone's age just from that. Mental age sure but what is mental age? Someone is older because he likes wine and the other likes soda? It is stupid and not needed. Waste of resources when there are more efficient way to go about it.