Rule of the very old. . . this does tend toward both stability (as that which may change things internally are repressed and external changes there is the well of experience to deal with) and could be a large factor. By the time a new person joins the geriatric oligarchy there have been centuries of normalization to fight against.

The second things I'd lean toward is that is that sociability is inversely correlated to lifespan. This could well be a matter of soul if you want. Elves could well be good at lots and lots of things but have a very low level of social specialization. This might not work for your world but would explain where all their skill points end up.




In a more multicultural ever-changing situation: Elves tend to prepare to fight the last war, they see so much of history that they are often thus not the best choice in some place of leadership. As new technology or social structures enter an environment the elf that was the master of the previous one may well be behind the 8 ball now. This doesn't translate well into most game mechanics but does in terms of how people generally work. So a human led tribe is far more likely to have the right person for today's challenge than the elf tribe who is looking at preindustrial economics or Napoleon's tactics as standard. And those groups who are able to balance the two would probably be the most successful.


.....Idea is developing.....

actually you could just make it harder to learn things as you get older in general.

Goblins generally die before anyone notices, it effects humans somewhat, only in the very long lived races are full effects seen.

Young elves could well be quite creative but their elders are basically trapped in the past....this drives them to keep things the same as they remember it (just to avoid embarrassment and getting lost) and frustrates the younger ones (some of whom respond by going on adventures)...its why Wyrm dragons regularly make references to long forgotten tribes as if they were still neighbors...its why the true immortals can fall because after a couple of draconic eras they can't learn at all and are as trapped in the past as the undead that can remember their births.