In my third and final post on the political economy of Westeros, I want to address a question that has bothered me about A Song of Ice and Fire since I was first introduced to it. Many of the Lords Paramount have ruled their part of Westeros for thousands of years. The Starks, the Arryns and the Lannisters are the most obvious examples, but there are many others. In our world, however, there is far more turnover in who rules and who serves. This is not to say that families never stay in charge for long periods of time, but precious few families have kept their surnames and crowns for more than a few centuries. And to my knowledge, none have done so for more than 2000 years, like the Starks and the Lannisters. So it struck me that this was one of the least realistic things about social life in Westeros besides magic, of course.

But now I’d like to offer a theory as to how their power persists: Weirwood-modified genetics. Consider the following:

• We know that some genetic effects in Westeros persist for very long periods of time. The Starks have long, brooding faces, and dark hair, the Baratheons have coal-black hair and the Lannisters have golden hair and green eyes, typically. The Targaryens, obviously, have silver-gold hair and purple eyes of various hues.
• We know that genetics can be influenced by magic, from GRRM’s own mouth (I heard this by report from Aziz and Ashaya at History of Westeros, but I can’t find the source through Googling.
• We have some reason to believe, following Greg Clark’s recent, extensive work in The Son Also Rises on the persistence of social advantages in many countries across history that there is probably some genetic basis for social dominance even in our world. In our world, the dominance of certain families lasts for generations longer than it should if some kind of social skill were not heavily heritable. In Westeros, this effect is far, far stronger for a few families.
• We know that nearly all the great castles have Weirwoods, including Casterly Rock and Winterfell (though the Eyrie has no weirwood, as the ground is too stony). Storm’s End, White Harbor and Riverrun all have weirwoods.
• We know that at least in White Harbor and Winterfell, the faces on the heart trees resemble the faces of the families. The heart tree in Winterfell has a “long and melancholy face” much like Jon Snow and Arya, Eddard Stark and Lyanna Stark. The face on the weirwood in White Harbor is carved on a “trunk so wide that the face carved into it looked fat and angry.” True, many different families have ruled from White Harbor, but the face seems to correspond to the incredible girth of the Manderly men.

So here’s my theory: weirwoods dramatically slow genetic drift for those who live in their presence on a day-to-day basis. The faces in the weirwoods even have an effect on the appearances of the families who rule there. Thus, the face on Winterfell’s heart tree shapes the faces of the Starks.

If social advantage is partly genetic, as appearance is, and weirwoods produce extreme genetic stasis, then so long as the Starks begin to live around the weirwoods at the right time, their social advantage will be retained far longer than those who do not live near weirwoods. We’ve never seen the weirwood at Casterly Rock, but if it doesn’t look clever, tricky and sly, I’d be very surprised.

The Arryns are a problem for my theory, as they have retained control for an extremely long time (at least 6000 years) and without a weirwood in recent memory. But there is no obvious common genetic appearance to the Arryns, as far as we know, so at least that’s consistent. But I still need to explain how they maintained their power for so long.

That said, I may have explained the dominance of many of the great noble houses.