In one of my tribes I have a 19 year old fathering a 6 year old. What happen? I mean he should be 22 to be fathering a 6 year old.

If the child was produced when the game was off, it's not surprising. The way that the game handles baby villagers during startup processing tends to produce a lot of kids the same age, from the same mom, and frequently of "impossible" ages, since the game considers only the mom's age when the game is started. Probably not very realistic, but that's how it works.

Really? Thats wierd. Maybe if you just started the game, the computer automatically generated a father and child. Also, if you have a large tribe, it's possible that you have two lookalike villagers. It certainly is a wierd problem, but if you post a little more information, maybe somebody can answer you more helpfully.

Edit: Ohh, looks like lady beat me to the job, LOL!