Ability scores count as Natural Abilities IIRC. Gaining pure mental stats due to age accounts as pure power gain and as ability gain. While you don't get it on every age category, it still qualifies, since there is no mention that you need to gain them for every age category progression.
There you go, and btw.. If I am not mistaken I am repeating this argument already over and over. So, how comes that you missed it?^^