Eugenics in D&D

November 9, 2006

I'm not much a fan of the d20 system.

Don't get me wrong, it's a vast improvement over earlier additions of Dungeons & Dragons. It just doesn't go far enough. You still end up with a bunch of guys around the table asking one another if they've found the second page of their character sheet or having discussions on whose dice collection is bigger. I don't see why you can't have a good time with three or four attributes and as many dice, but when one of my buddies asked if I was up for a game, I said what the hell.

But the fun really started when he said he was putting together a completely new game world and we could make our own race. You'd think that when you're dealing with someone who has an account on childrenofmillennium.org, the idea of eugenics will show up in one form or another regardless of whether a genuine conversational opening appears, but he must not have been thinking very hard about it, because of course, I wanted my character to come from a race which had practiced selective breeding on its members for the past 500 years.

And of course, he realized too late just what that would mean.

Most D&D afficionados know of eugenics as either some creepy Nazi fantasy or else as an excuse to give Tyr Anasazi arm blades. It never occurred to them that the wide variety of Horses in the equipment list just might have resulted from wise breeding practices. And it definitely never occurred to them that you could use it to get a race with +5 to all six attributes, which is funny because munchkins will try any sleazy, underhanded trick to end up with an overpowered character.

That's what the Game Master thought I was doing too, at first. But it wasn't. I agreed off the bat to start out two levels below the other Characters (who were starting at 3rd). There wasn't much he could say to that, so the next thing you know I've showed up to the first game session with my Superman.

The interesting part was when the other players found out about my character's race. Ignorant, foolish, stupid claims were made that I'd done the impossible. But from a theoretical standpoint there was nothing even very unusual about it. I reasoned on the basis of modern studies that A) most of the attributes were about 50% heritable, and once you know a trait's heritable, the only things left to do are B) decide how you're going to boost it and C) figure out how far it improves.

Point A took the most consideration. Although a character's attributes are meant to be enduring traits which don't change much over the course of his adventuring life, that by itself doesn't tell you how heritable each one is. So I'll check them out individually:

STRENGTH: Because of its obvious relationship to height, which is highly heritable at over 90% by adulthood (check here), Strength would also have a very high heritability. Of course sheer height alone doesn't define muscle mass because a person can be strong or skinny for his frame. Weight is probably an even better measure, and it's got a heritability in the neighborhood of 70 to 86% (no I'm not making this up). Combining these two measures and taking a conservative average gives us a nice round estimate for the heritability of Strength at 80%.

DEXTERITY: This is one of the toughest attributes to calculate heritability for. The 3rd Edition PHB calls it "hand-eye coordination, agility, reflexes, and balance" but you're going to have a tough time finding heritabilities for any of that stuff in real life. Well maybe not quite; we can infer that Agility is just a person's strength to weight ratio which can more or less be reduced to obesity (or its lack) which has a heritability of 40% (see this page). After a ton of digging, I figured out that they've actually done studies on reflexes under the name "reaction time" but that it's only about 15% heritable (check this study). But the heritability of hand-eye coordination is quite the opposite, if you believe this study: "The heritability in movement accuracy as assessed by the displacement from the target at 70% maximal velocity was 0.87" but another study using what I can only assume was a different methodology gave 41% for "hand motor skill" (check here). What about balance? Also heritable according to this study: "Heritability was 46% for the 'sensory balance tests' factor and 30% for the 'static and dynamic perturbations' factor." This collection of heritabilities is pretty different from one estimate to the next so taking a single average seems pretty funny. Still we can at least say that Dexterity is heritable, and the heritability looks to be somewhere near 40%.

CONSTITUTION: A little common sense says that Constitution would be largely environmental since genes promoting ill health tend to die out with their hosts. But they never get removed completely or else there wouldn't be things like Parkinson's disease or Hemophilia around. The trouble is that these are all specific disorders and we're looking for a general sort of measure which will be tough to find. But there are still a couple of ways of getting at it. If you just ask people "how healthy are you" you find out that the heritability of their answers is more than one-third (yes, really). And if you prefer to see a more objective measure, just check out the heritability of longevity which is also exactly .33 (no kidding). That's heartening because it's extremely similar to the previous finding. We're probably on the right track here: Constitution seems to have a heritability of around 35%.

INTELLIGENCE: This is the easiest attribute to get a heritability for. The American Psychological Association reports that adult IQ scores have a heritability of around 75% (just check Wikipedia).

WISDOM: Another tricky one. There were a lot of arguments about this one which is what made me decide to go back and calculate heritabilities for all the others. The 3rd Edition PHB defines Wisdom as "willpower, common sense, perception, and intuition." Willpower is a lot the same as Conscientiousness, right? You've gotta figure that someone who is organized and can persevere at difficult tasks is wiser than someone who is lazy and scatterbrained (hey don't make fun of me). You could say that willpower is also the opposite of Neuroticism because an anxious, angry, panicky sort of person isn't going to behave in a very consistently wise fashion. Fortunately the heritability of both Conscientiousness and Neuroticism is around 40% so whether or not you think Neuroticism should be included, you get 40%.

Unfortunately "common sense" is really just intelligence. Since wisdom is supposed to be unrelated to intelligence, we'll just ignore this one. Next is perception. Variation in the ability to see and hear things is obviously highly genetic. As far as eyesight goes, "The estimated heritability of refractive error was 61%" (according to this study) and as far as the ability to discriminate between pitch "Genetic model-fitting techniques supported an additive genetic model, with heritability estimated at 0.71 to 0.80" (look here). Last of all we have intuition. Dictionary.com defines it as "direct perception of truth, fact, etc., independent of any reasoning process; immediate apprehension" which I really don't believe in as such. (Some might say that it's just intelligence operating subconsciously but again wisdom isn't supposed to be related to intelligence.) We'll just assume this is something the gods whimsically bestow upon some people which affects their talent in using priestly abilities: heritability zero.

Although these heritabilities are very different one to the next, it isn't because we've got different measures of the same thing so much as that we've got one attribute that's really made up of a bunch of unrelated parts. Average it all together and round down and you'll get the heritability for Wisdom at 40%.

CHARISMA: Because it's basically just a combination of looks and leadership ability, is probably an amalgamation of attractiveness and Extraversion. The heritability is Extraversion is known to be from 40 to 60% (just ask Wikipedia!) and one study on physical attractiveness found the heritability was more than 60% (click me I am a big important link). So by conservative estimates the total heritability of Charisma is going to be around 50%.

Now that we've established that the six attributes really are heritable, we can move onto Point B and establish how exactly we're going to accomplish this eugenic boost. In modern times there are all sorts of options, but in a fantasy world you're pretty much left with government coercion and regulation, or religious/cultural values. Since I don't think the former works at all, I went with the latter. That meant a society of visionaries devoted to future generations and a general alignment of Neutral Good (not my favorite, although maybe that says something about why "Good" even evolved at all in the real world - groups beat individuals any day, and a group only really works if the individuals make honest sacrifices). These people probably didn't have a very good understanding of genetics beyond basic animal husbandry, but under the guidance of a network of Druid elders they should be able to arrange a few marriages between the most gifted youngsters and encourage the others to moderate their reproduction and perhaps adopt children from the elect if they need help working on their farms.

Although there are many ways of working out the details, I imagined that the society would have been founded by the followers of a naturist religion who staked out an area of wilderness to watch over. Although it occured to me that I could have involved deities or long-lived guides of some kind, I preferred that they were watched over by an enclave of druids who took it upon themselves to maintain the genetic quality of their people as well as their land. And while there aren't any spells in the PHB which specifically deal with evaluating attributes, even low-level Druids have access to abilities which are very similar in their effects like Detect Animals or Plants. So even a mid-level Druid would be more than enough to evaluate the genetic quality of the people, and would probably also have either supernatural abilities or else some herbalist knowledge that dealt with of ways of increasing fertility among the selected couples and decreasing fertility among the general populace which would allow the selected couples to have three or four times the birth-rate of the others.

So we're left with point C. I'm no statistician, but I know that the upper 2% in a 3d6 bell curve is around 17. (There is one way to get an 18 and there are 3 ways to get 17 on 3d6 out of 6^3 = 216 possible combinations and thus 17 is the cutoff for upper 2%.) That means that a 17 in any attribute is at the +2 Standard Deviation mark. And if 17 is 6.5 points up from the average of 10.5 that means 1 SD is 3.25 (or around 3) points. How fast can a society boost a trait by 1 SD? Without even meaning to, American society is reducing its intelligence by around 1 IQ point (i.e. 1/15 of an SD) per generation (where a generation is about 25 years). Committed hardcore eugenicists could probably go at five times that speed, but I figured there was no point in making claims people would shoot down, so I figured on only 1/12 of an SD a generation. Of course, this is intelligence we're talking about, and some of the attributes are less heritable. Since traits change under selection pressure in proportion to their heritability, Dexterity, Charisma, and Wisdom would probably change at a little better than half that pace, with Constitution improving a little more slowly than half speed.

This means that after 500 years have passed, we are looking at a race of people with +5 in their Strength and Intelligence, +3 to Dexterity, Wisdom, and Charisma, and +2 to their Consitution: beautiful, brilliant, strong, graceful, healthy, even wise people, given that the Druids would value this characteristic above all others and would press for its improvement along with the others.

After I ran through the numbers, there was still some skepticism from the other players, who still seemed to think that there was something "too good" about a fighter with 20 intelligence. They questioned whether the attributes really were genetic at all, and said that there should be some "tradeoff." But even if you ignore the scientific studies it's common knowledge that things like strength or intelligence are at least partly genetic, and even wisdom is defined as "willpower, common sense, perception and intuition," and at least two of those things (willpower and perception) do have an obvious genetic component. As far as the idea that a eugenic race is too good because there was no tradeoff in my attributes, the whole point of eugenics is that the tradeoff happens when you start it. Current generations agree to modify their behavior somewhat to take into account the genetic health of future generations. If you come from a race of people whose forefathers planned and built rather than just wasting their lives, you start out with a leg up in the world, simple as that. It's really no different from a group of people saving up food in granaries or building aqueducts for future generations to use.

And then when the other players finally realized that it was on the level, when they realized that yes, this would work, it started to dawn on them: "You know what? People could do this in the real world!" Of course, it's too bad that the real question never occurred to them: "Why haven't people already done this in the real world?" Because its a damn shame that they haven't yet. But don't worry. We're working on it.