How can age be determined?

Question

I am thinking of the Polygamist sect. The people are alive and have no official documentation. Thanks in advance.

Answer 1

Age can be determined, there are stages of growth that all people go thru.

Answer 2

There is documentation of every birth event that occurred in the compound.  Official documentation is not necessary to make a fact a fact. If your speaking of a birth certificate, those who were born into that population will be issued one based on the results of the genetic testing, and the recorded data that exists.    The Mormon church has many social programs in place that will be accessed to provide the children of the sect with opportunities to unlearn, and relearn.