Harry Potter and The Methods of Rationality

[felice]

I think a squib has very weak magic, rather than none? Or possibly there isn't any difference.

Muggleborns seem to be more common than squibs, though, and it seems unlikely that Rowling intended for the blood purists to be right. Maybe the magic gene is just extra-prone to mutation resulting in the occasional squib popping up (even in pureblood families) - seems far more plausible for it to fail occasionally than for it to repeatedly appear spontaneously in the muggle population. A muggleborn wizard would only be born when two muggles with the magic gene (ie squibs unknown to the magic community) got together, and even then only a one-in-four chance; that seems sufficiently rare to match the observed frequency of muggleborns, despite the vast numbers of muggles.

[fionwe1987]

The magic gene can't be dominant. If it were, there would be no explanation for muggle-borns. One of Hermione's parents would have to be magical.

As for the claims of the blood purists being proved in this scenario... there are two things against it. While intermarriage may prevent the birth of squibs (no guarantee though. Being a squib may simply be a genetic disease), it also causes other instabilities, giving rise to people like Voldemort. Second, while the number of squibs in the original pureblood families may go up if they married with muggles, the overall number of witches and wizards will definitely rise as the magic gene spreads out of the small community and into the muggle populace.

[Eneasz]

I'm guessing that convincing anyone to read Harry Potter fan fiction is going to be one hell of a hard sell. If it wasn't absolutely brilliant and one of the best pieces of writing i've read so far this year I wouldn't have even tried. Luckily a lot of people (no, really, there's even been a readers meet-up) have been praising the work already so I can just quote them!

Oh, and for what it's worth, I first found out about this when David Brin recommended it.

Link

I'm a little late here, but for those who are pressed for time to read, Harry Potter and the Methods of Rationality is also being put out as an audio-book, in the form of a free podcast (new chapter every Wednesday). Here at iTunes, or directly at hpmor.libsyn.com

[Nerdanel]

Consider the relative populations of the Muggle and the Wizarding worlds. Rare events such as mutations affecting the wizard gene would happen far more times in Muggle families simply because there are so much more common. Thus it is more plausible to treat the Muggleborn wizards as mutants rather than the Squibs born in wizard families.

I also noticed that there is another factor. Harry has, ironically enough, been assuming that everyone's social parents are their biological parents. Remember how casual Draco was about rape? I suspect a lot of Squibs and Muggles get taken advantage of and later give birth to wizard children. I think the fic might be going for Harry later on having to realize that he had made a mistake about this.

The Blood Purists are wrong because they do not understand that 1) having one or two wizard genes are equally effective for magic, and 2) genes are discrete and cannot get diluted, and 3) the most effective middle-term way to increase the total magical talent on Earth would be for everyone witch and wizard to produce children with Muggles instead of each other.

[Gaston de Foix]

so a question for the readers here- is the author adding any more chapters or not? Because I looked at the chapter titles and they don't seemed to have changed for a while...

[afterroots]

Yes, more chapters are to be written. The author seems to be having trouble of late finding the motivation to write though so the pace has slowed down quite a bit.

[felice]

Consider the relative populations of the Muggle and the Wizarding worlds. Rare events such as mutations affecting the wizard gene would happen far more times in Muggle families simply because there are so much more common. Thus it is more plausible to treat the Muggleborn wizards as mutants rather than the Squibs born in wizard families.

If there was a single gene for being a wizard that was on or off, sure. But the planet should be overrun with Muggleborns if that were the case. It seems more likely that it's a complex signature of multiple genes on a chromosome, and the chances of that reoccurring by random mutation on a regular basis is vanishingly small. A complex signature would be fragile, too, with the mutation of any single gene in the signature (and it could be millions of pairs long) being all that's needed to produce a squib - which could relatively easily spontaneously reverse in some distant muggle descendant generations later.

I suspect a lot of Squibs and Muggles get taken advantage of and later give birth to wizard children.

I'd expect the blood purists to have noticed that; they hate the idea of wizards being born to muggles, and would have figured it out if the muggles they raped kept producing wizard children. They don't have any need to conceal their indiscretions from each other, so the pattern should become obvious after a while if virtually all their illegitimate offspring shows up at Hogwarts twelve years later. If they were capable of denying the existence of muggleborns, they would have done so. But if they were introducing a recessive wizard sequence into the muggle gene pool, the seemingly random appearance of muggleborn wizards generations down the track would be far less obvious.

[SerArthurHeath]

As soon as the conservation of matter was mentioned in chapter 1 or 2 I was won over. Plus, in this story, Voldemort's not a moron whose idiocy destroys any dramatic tension in the entire story, and I'm not scared of a ludicrous deux ex machina meets collect the plot tokens ending

[Maester Joergensen]

I have read the first few chapters and will propably keep reading if the quality keeps up. I am enjoying it mostly through the fact that I am a rationalist, and it enforces my own worldview. I will have to see where it goes. I am a little worried about Harrys character. I might end up really disliking him is he keep carrying on like this. I really enjoyed harry Potter for what it was, and really loved PON. But I think I wouldn´t have liked PON so much if Kellhus had been the only main character instead of having people like Drusas Achamian. It should be possibly to be a rationalist without being a complete prick. Or what do you think. I know I am making an effort myself. Also, do people think this kind of literature can really shift peoples worldview, or is he preaching to the choir?

[TerraPrime]

Re: Genetics

Presuming that we're talking about a single-locus trait, meaning that the phenotype (ability to use magic) is determined by a single gene, there are many good reasons why the described pattern in the book may not fit the dominance/recessive predictions.

First, just because there is a single locus it doesn't mean that there are two alleles (yes magic/no magic). It's possible that there are multiple versions of the gene, much like say coat coloring for many animals (cats have white, tan, and black, for instance). So it's possible that there are 3 to 4 alleles for the same gene, varying in strength.

Second, alleles do not just interact in one way - dominance and recessive. The interactions between alleles can be complex. There 2 other types of allele-to-allele interactions: incomplete dominance, and co-dominance.

The dominant/recessive interactions is what has been discussed here so far. This is the case where the combination of A1/A2 alleles will express only 1 of the alleles, say, A1. An example would be one of Mendel's classic pea experiments, like pea color. The yellow color is dominant to the green color, so in a combination of yellow allele/green allele, you get yellow peas. Yellow is dominant to green and green is recessive to yellow.

The incomplete dominance scenario is where A1/A2 combination leads to a phenotype that is intermediate of the two alleles. An example would be snapdragon flower coloration. A red snapdragon flower crossbred with a white snapdragon flower will create a pink one. The red color is dominant to white, but the effect is diluted.

The co-dominance scenario is where A1/A2 combination leads to expression of both alleles at full strength. An example would be our ABO blood type system. The allele for A and B type are co-dominant, meaning that the person with the A/B combination will become blood type AB, not intermediate, not A, and not B. While incomplete dominance and co-dominance both express both alleles, the difference is that co-dominance expresses both alleles to the full strength and incomplete dominance expresses both alleles at reduced strength.

Third, not all alleles behave consistently from generation to generation. For instance, the famed Hapsburg jaw is a dominant trait, but it suffers from incomplete dominance, meaning that the dominant allele that leads to the Hapsburg jaw is not always expressed, but when it is expressed, it's dominant. Another confounding factor is variable expressivity. This is where a full set of phenotypes are not always present. An example would be the Marfan syndrom, that can cause skeletal, ocular, and muscular deformities. However, not all patients with Marfan syndrom suffer from all 3 types of defects - some only have defects in skeletal and ocular defects, etc.

So if we take into consideration all these real-life examples, we can explain much of the observed variances in the Potter world. Of course, unless Rowling had an extensive and written pedigree of major wizard families, we cannot determine if any of the above explanations are applicable. I also do not know that Rowling had written her work with these biological realities in mind or not. This is college level genetics for those who major in genetics, i.e. this is not something that's usually covered in introductory level. It's certainly researchable, though, even through Google.

That said, there are some examples in the book that can fit one of these descriptions. For example, the ability to become an animagus seems to be both trainable as a form of transfiguration, but also can be inborn. This might be an example of variable expressivity.

Now, to explain both the appearance of squibs and the appearance of wizards born to both muggle-parents with no apparent history of magic in the family before (like Herminone), we can propose that there are 4 alleles with varying ways of interacting and behaving towards each other. I'll call these alleles M1, M2, M3, and M4, and hypothesize the following interactions:

M4 - contributes nothing to the ability to use magic

M3 - contributes 15% to the ability to use magic

M2 - contributes 40% to the ability to use magic

M1 - contributes 60% to the ability to use magic

The threshold to be able to use magic is 50%.

So most wizards are M1/X. A wizard with M1/M2 marrying witch with M1/M3, for instance, will always produce magic users (M1/M1, M1/M3, M1/M2, or M3/M2 all exceed 50%). However, a wizard who is M1/M2 marrying a witch who is M2/M4 will have a 1/4 chance of producing a squib (M2/M4). Similarly, if we propose that Hermione's parents are M3/M4 and M2/M4, then she could be M2/M3 and would be a magic user. Also, Lily and Petunia's parents can be M3/M3 and M2/M4. Lily could then be M2/M3 and Petunia could be M2/M4.

The explanation can become exponentially more complex if we start looking at multi-loci determinants, where a single trait is determined by the additive effects from multiple genes, such as our height.

[Shryke]

I have read the first few chapters and will propably keep reading if the quality keeps up. I am enjoying it mostly through the fact that I am a rationalist, and it enforces my own worldview. I will have to see where it goes. I am a little worried about Harrys character. I might end up really disliking him is he keep carrying on like this. I really enjoyed harry Potter for what it was, and really loved PON. But I think I wouldn´t have liked PON so much if Kellhus had been the only main character instead of having people like Drusas Achamian. It should be possibly to be a rationalist without being a complete prick. Or what do you think. I know I am making an effort myself. Also, do people think this kind of literature can really shift peoples worldview, or is he preaching to the choir?

You'd think so, but there's a reason "Kant" and "Cunt" sound so suspiciously familiar.

[Timbits]

Some fanfic is actually pretty darn good and even original. My friend once sent me a twilight fanfic (I know I know, terrible book) and it was surprisingly very well written and enjoyable. The concept didn't have anything to do with that book at all, pretty much just used character names. I'm a little ashamed to admit I've read a twilight fanfic though :).

[fionwe1987]

So if we take into consideration all these real-life examples, we can explain much of the observed variances in the Potter world. Of course, unless Rowling had an extensive and written pedigree of major wizard families, we cannot determine if any of the above explanations are applicable. I also do not know that Rowling had written her work with these biological realities in mind or not. This is college level genetics for those who major in genetics, i.e. this is not something that's usually covered in introductory level. It's certainly researchable, though, even through Google.

Was google available when Rowling was writing? And did she have access to the internet?

But she may well have checked up in a library, or have a friend explain.

Now, to explain both the appearance of squibs and the appearance of wizards born to both muggle-parents with no apparent history of magic in the family before (like Herminone), we can propose that there are 4 alleles with varying ways of interacting and behaving towards each other. I'll call these alleles M1, M2, M3, and M4, and hypothesize the following interactions:

M4 - contributes nothing to the ability to use magic

M3 - contributes 15% to the ability to use magic

M2 - contributes 40% to the ability to use magic

M1 - contributes 60% to the ability to use magic

The threshold to be able to use magic is 50%.

So most wizards are M1/X. A wizard with M1/M2 marrying witch with M1/M3, for instance, will always produce magic users (M1/M1, M1/M3, M1/M2, or M3/M2 all exceed 50%). However, a wizard who is M1/M2 marrying a witch who is M2/M4 will have a 1/4 chance of producing a squib (M2/M4). Similarly, if we propose that Hermione's parents are M3/M4 and M2/M4, then she could be M2/M3 and would be a magic user. Also, Lily and Petunia's parents can be M3/M3 and M2/M4. Lily could then be M2/M3 and Petunia could be M2/M4.

There's a problem with this. We know of two Muggle born witches who seem to have exceedingly high magical ability. Maybe Lily was M2/M2 and was thus a powerful witch, but unless Hermione is M1/M1 or M1/M2 I see no explanation for her exceptional abilities in this theory. She's clearly far more powerful and skilled than any of her compatriots, and the books seem to imply that this is more than just the fact that she's a borderline genius.

And even if we vary the numbers in your hypothetical, the fact that a muggleborn's abilities so far exceed the ability of any single Hogwart's student we've seen seems to weaken the possibility of this theory.

I do agree though that a more complex allele interaction scheme may be at play. And the fact that this isn't explored in the book (the fanfic) may well be a pointer to Harry not being that clever.

[felice]

A more complex allele interaction is certainly possible, but a straightforward recessive trait is a good fit for the data Draco collects. And in the fic, if not the original novels, magical strength seems to be entirely a matter of knowledge, skill, and practice, not genetics.

[Herr Fick]

I haven't read it yet but would like to know what kind of "rationalist" Potter is in this story. Is he a rationalist in the traditional sense of the term (as opposed to an empiricist)? Is he a critical rationalist (like Popper and Albert)? Or does he simply adhere to some set of rules supposed to constitute a 'scientific method'?

[Snowy89]

I haven't read it yet but would like to know what kind of "rationalist" Potter is in this story. Is he a rationalist in the traditional sense of the term (as opposed to an empiricist)? Is he a critical rationalist (like Popper and Albert)? Or does he simply adhere to some set of rules supposed to constitute a 'scientific method'?

He's a megalomaniac rationalist genius boy, bent on world domination, the first few chapters are seriously incredibly funny.

On Ghost Busters music during the choosing ceremony he gets them singing:

Who you're gonna call, what you're gonna do when the Dark Lord comes for you?

Harry Potter, Harry Potter!! :lmao: :lmao:

[Migey]

That scene with the ghostbusters music in the great hall was pure awful. One of the worst in the book. What follows immediately afterwards with the sorting hat is awesome enough to make up for it though, as well as the fact that the book as a whole is just genius.

I love the way he worldbuilds. Alot of it doesn't make sense if you havn't read the original Harry Potter series, but reading TMoR I realise how bad Rowling was at actually creating and substantiating her world. There are alot of little tid bits in this book - from the story behind Grindlewald to Moody's eye, and say the differences between magical America and magical Britain.

Awful as Harry Potter was, having read TMoR, i feel that all 7 books in the original Harry Potter were worth reading, just to appreciate this one. I hope Less Wrong continues to write. I'm just imagining how awesome it would be for TMoR to continue to something over 200 chapters.

[TerraPrime]

Re: fionwe and felice

I am not sure whether power in magic is the same as ability to use magic. In the canon, we have wizards of varying strength. For instance, Ginny is more powerful than probably all her brothers, though that could be the 7th child of a 7th child at work. So it is possible I think that there are sets of genes, one for unlocking the ability to use magic, and the other for how much raw power you can wield. I don't think the books are clear either way.

At any rate, I think the most genetically consistent system of magic ability is actually in Melanie Rawn's Sunrunner series. I think she for sure did her homework on Mendelian genetics when she designed the magic system. I think Rowling's world is less reflective of reality and while some of these explanations can fit, it's probably not something that she had planned. I could be wrong, of course, unless she decides to release her notes (I doubt it).

[fionwe1987]

Re: fionwe and felice

I am not sure whether power in magic is the same as ability to use magic. In the canon, we have wizards of varying strength. For instance, Ginny is more powerful than probably all her brothers, though that could be the 7th child of a 7th child at work. So it is possible I think that there are sets of genes, one for unlocking the ability to use magic, and the other for how much raw power you can wield. I don't think the books are clear either way.

Wasn't Maolly the third child? And I don't really know where Ginny stands in relation to Fred, Geaorge or Bill. Is she really stronger than them?

As for there being a completely different gene that determines talent... could be. There does seem to be some clustering of magical ability, but cases like Hermione's do seem to throw it off.

At any rate, I think the most genetically consistent system of magic ability is actually in Melanie Rawn's Sunrunner series. I think she for sure did her homework on Mendelian genetics when she designed the magic system. I think Rowling's world is less reflective of reality and while some of these explanations can fit, it's probably not something that she had planned. I could be wrong, of course, unless she decides to release her notes (I doubt it).

Haven't read Sunrunner. But Jordan seems to have a pretty good grasp of it too. Sergei Lukyanenko's Watch series seems to have a genetically consistent model too.

[AverageGuy]

As for there being a completely different gene that determines talent... could be. There does seem to be some clustering of magical ability, but cases like Hermione's do seem to throw it off.

I don't know about magical "power" in the HP world. I always thought Hermione's abilities were related more to her intelligence. She usually learned the spells faster, but once she did, her spells didn't seem to pack any more oomph, e.g. her patronus compared to Harry's and Ron's.