That's not due to alignment, its just that most of the races that enjoy raiding their neighbors for gigles (aka races that are evil by nature) we have seen so far have been goblinoids. Goblinoids don't seem to live much longer than humans, but they are said to have high fertility. Other evil races such as drow and duergar live as long as their counterparts which is balanced by those races having low fertility. That's true for sprites as well. Pixies are an odd race as they have both high fertility and presumably lifespans long enough to match their sprite counterpart. On the other hand, regular pixies cannot learn skills. Which I guess means they cannot use anything apart from the most basic of weaponry, armor and mounts. Checks and balances. ¨ Many of other races have an advantage in lifespans and extra stats per level. Humans on the other hand have the advantage of breeding several times faster, allowing them to much more easily rebuild their population after a war as well as far more rapid expansion. At the same time humans have managed to mostly avoid the mindset of the goblins where everyone is expendable and everyone had better keep an eye on everyone else. As individuals other races often have the better deal, but there is a reason humans dominate so much of the eastern river peninsula as a race.