Allomantic genealogies

[Caelan]

Just starting wax and Wayne. Talking about compounders and twinborn is super interesting but it’s got me wondering if we know how frequent twinborn are and also if my dad was a coinshot could I be a tineye and my sister be an augur or something like this? 

[Trusk'our he/him]

1 hour ago, Caelan said:

Just starting wax and Wayne. Talking about compounders and twinborn is super interesting but it’s got me wondering if we know how frequent twinborn are and also if my dad was a coinshot could I be a tineye and my sister be an augur or something like this? 

Welcome to the Shard!

We don't have any true numbers for most of these yet, but Metalborn themselves are not terribly rare. Less than 1 out of 50 people will be Metalborn though, but we don't have exact numbers. Twinborn will be rarer than Ferrings or Mistings.

Spoiler

https://wob.coppermind.net/events/101-conquest-46/#e882

Kaymyth (parapharased) (paraphrased)

I asked another question about the population levels of Mistings, Ferrings, and Twinborn.

Brandon Sanderson (paraphrased)

The numbers in the [Alloy of Law Mistborn Adventure Game] supplement are off. (It states the occurrence of Mistings/Ferrings is 1 in 50 people.) He said that they're not terrible, but they definitely are shown as somewhat more common than they really are. But he also said that they're not nearly as rare as people seem to think; for example, he stated that virtually everyone would know at least one Coinshot. So there are definitely a lot of Allomancers around.

And the occurrence of Twinborn would not be a normal statistical spread (alas).  As folks opined before in this thread, the Terris folk do tend to keep somewhat to themselves, so there's not a huge amount of population mix.  So Twinborn will be rarer.

I did point out that there had to be some mix, else we'd be seeing full Feruchemists around, and to that he mostly just smiled and looked mysterious.  As he does.

 

Footnote: Kaymyth later clarified that Brandon said that the MAG numbers are too high.

We learn in passing in book 3 of Wax and Wayne that there have only ever been 3 Crashers (Allomantic steel/Feruchemical iron Twinborn) recorded in Scadrial's history. Assuming Compounders are as likely to exist as any other Twinborn type (which may not be entirely true, it's been debated whether certain types of powers like Allomantic steel are more common than others) you could very roughly expect a single Compounder of each type to exist once every century.

It also should be noted that the type of Allomancer or Feruchemist you are appears to be mostly random- you'll have a higher chance of having one if your parent had one, but you won't necessarily be the same type of Metalborn power.

Spoiler

https://wob.coppermind.net/events/547-fanx-2025/#e16958

Questioner

In the Mistborn magic system, being an Allomancer is hereditary. If two identical twins were born to nobleman parents and they were Mistings, would one of them be able to have powers and the other couldn't? Or would they both have to have powers? Or, if they were both Mistings, could they have different Misting powers?

Brandon Sanderson

Most likely occurrence is that they would have different Misting powers. Because while it is hereditary, remember, in the cosmere you have both what we call a spiritual DNA, your Connections and things on the Spiritual Realm, and physical. They're gonna be close enough that it would be really, really rare that both wouldn't have powers. It would be most common that they'd have different powers, but not too infrequent they'd have the same one.

 

[Akimikoisthecutest]

1 hour ago, Caelan said:

Just starting wax and Wayne. Talking about compounders and twinborn is super interesting but it’s got me wondering if we know how frequent twinborn are and also if my dad was a coinshot could I be a tineye and my sister be an augur or something like this? 

I think so, I believe that the Allomantic gene is just a connection to the shard of preservation, so yeah! You totally can have different allomantic abilities in the same family.

[Nitpicking]

This isn't based on anything Brandon has said, either in a story or a WoB.

Just based on my own training in biology and statistics, I think any Scadrian or part-Scadrian has a chance, ranging from tiny to small, to be an allomancer. See, they all have a stronger connection to Preservation than, say, a Nalthian. We know that Preservation was weakened because it divided itself and gave a bit of its power to each Scadrian, in a way not totally different from how Endowment gave a piece of itself (Breath) to every Nalthian. (Side crackpot theory: this did NOT weaken Endowment. Endowment's power and role is literally giving gifts. Giving some of itself to other people to use as they will is so congruent with its Intent that it actually strengthened Endowment.)

Since every Scadrian has extra Preservation within them, any mating between them could randomly result in sDNA giving the offspring higher-than-average Connection to the Shard, and thus an allomancer.

Note that this reasoning doesn't really apply to feruchemy, because that also requires being born with a strong connection to Ruin, and Ruin didn't gift itself to the humans of Scadrial. (Could Sazed balance himself by doing that, by giving every Scadrian a dose of Ruin equal to their already-existing extra Preservation? Would that cause an explosion of feruchemy? Would it buy the favor of Endowment, goddess of generosity?)

I realize this is more speculation than an answer to the original question. Moderator, feel free to move it to the Cosmere Discussions forum.