# Select only smart people for a colony. Do their descendants remain smart? **URL:** \ **Category:** Great Debates\ **Created:** [August 13, 2012, 3:20am UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341 "2012-08-13T03:20:21Z")\ **Posts on this page:** 8\ **Page:** 4
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [August 14, 2012, 5:39am UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/61 "2012-08-14T05:39:29Z")
> [@Sunspace](#): > > They interbreed with each other and the generations pass. Would the total population remain smarter, stronger, etc than the average of the people they left behind? Yup, although not necessarily as smart/strong or whatever as the parents (there would be [some regression to the mean](http://infoproc.blogspot.co.nz/2010/07/assortative-mating-regression-and-all.html)): > [@](#): > > The results are stated further below. Once you plug in the numbers, you get (roughly) the following: > > Assuming parental midpoint of n SD above the population average, the kids’ IQ will be normally distributed about a mean which is around +.6n with residual SD of about 12 points. (The .6 could actually be anywhere in the range (.5, .7), but the SD doesn’t vary much from choice of empirical inputs.) > > So, e.g., for n = 4 (parental midpoint of 160 – very smart parents!), the mean for the kids would be 136 with only a few percent chance of any kid to surpass 160 (requires +2 SD fluctuation). For n = 3 (parental midpoint of 145) the mean for the kids would be 127 and the probability of exceeding 145 less than 10 percent. > > No wonder so many physicist’s kids end up as doctors and lawyers. Regression indeed! 😉 Also, discussed [here](http://infoproc.blogspot.co.nz/2008/10/regression-to-mean.html): > [@](#): > > Now consider a population of +4 SD men married to +4 SD women. (More generally, we can consider a parental midpoint value of X which is simply the parental average in units of SD.) Suppose they have a large number of children. What will the average X be for those children? > > If we treat the environment E as a truly independent variable (i.e., it is allowed to fluctuate randomly for each child or family), then the children will form a normal distribution peaked at only +2 SD even though the parental midpoint was +4 SD. In other words, given the random E assumption the kids are not guaranteed to get the environmental boost that the parents likely had. Most of the parents benefited from above average E as well as G. This is called regression to the mean, a well documented phenomenon in population genetics that was originally discovered by Galton. > > Regression to the mean implies that even if two giants or two geniuses were to marry, the children would not, on average, be giants or geniuses. On the positive side, it means that below average parents typically produce offspring that are closer to average. > > How reasonable is this model for the real world? I already mentioned that regression is confirmed by data. (In fact, one uses this kind of data to deduce the heritability of a trait - the relative contributions of G and E need not be equal.) An interesting possibility in the context of intelligence is that, perhaps due to the modern phenomena of assortative mating and obsession with elite education, E and G can no longer be treated within the population as indpendent variables. In this case we should see a reduction in the level of regression to the mean among the intellectual elite, and further separation in cognitive abilities within the population. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [August 14, 2012, 9:50am UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/62 "2012-08-14T09:50:07Z")
> [@Sunspace](#): > > What would happen if we took a few hundred thousand people from the top 1% of humanity and isolated them to start a new colony? > > Let’s say, Mensa members, Olympic athletes, rich people who have earned it themselves, social geniuses… all people who drew genetic winning cards and either grew up in environments where they flourished or had the strength to overcome their non-flourishing environments. We might also consider that the default assumption here is that this would be a well-functioning society. Well-functioning enough to reproduce in any kind of stable fashion. I don’t think it would be. If you took all the brightest people–even assuming they are socially well-adjusted in a broad society–and made a society out of only them, you wouldn’t have many followers. To properly implement a successful eugenics program, you’d need to have fairly well-enforced structure that creates hierarchies in a world where everyone is an alpha genius. Too many chiefs; too few Indians? Who does the drudge work in such a society before Rosie the Robot is invented? A second item worth mentioning is (idle speculation) on whether or not physical ability and mental agility are at odds, genetically. Dumb jocks; weakling scientists. If it turns out there is a genetic underpinning to “really smart or really fast, but not both” then you have a second problem. Suppose, for instance, that testosterone-like hormones drive physical prowess but at the expense of brain prowess, and a given evolutionary environment has to make a trade for one trait or the other, but not both. ---
**Author:** ![Lynn\_Bodoni](https://avatars.discourse-cdn.com/v4/letter/l/e47c2d/32.png) [@Lynn\_Bodoni](https://boards.straightdope.com/u/Lynn_Bodoni)\ **Post date:** [August 14, 2012, 2:39pm UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/63 "2012-08-14T14:39:33Z")
One of the things that Mensa plays up is that their members are in all walks of life. There are rocket scientists in Mensa, and also janitors, for instance. Now, I’ll grant you that IQ tests will only measure certain kinds of intelligence, but I’d say that having a high intelligence doesn’t necessarily mean that the person will be a leader. Some are content to be followers. I would imagine that there might be fewer pure drudge jobs, and that each person would have to clean up after him/herself more, and also that the general drudge work would be rotated. ---
**Author:** ![greenslime1951](https://avatars.discourse-cdn.com/v4/letter/g/e9bcb4/32.png) [@greenslime1951](https://boards.straightdope.com/u/greenslime1951)\ **Post date:** [August 14, 2012, 7:18pm UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/64 "2012-08-14T19:18:17Z")
> [@Lynn\_Bodoni](#): > > One of the things that Mensa plays up is that their members are in all walks of life. There are rocket scientists in Mensa, and also janitors, for instance. Now, I’ll grant you that IQ tests will only measure certain kinds of intelligence, but I’d say that having a high intelligence doesn’t necessarily mean that the person will be a leader. Some are content to be followers. I would imagine that there might be fewer pure drudge jobs, and that each person would have to clean up after him/herself more, and also that the general drudge work would be rotated. I can only imagine with horror a society made up of Mensa members. I have gone to a few social functions (as well as their Annual Gatherings) a few times and I have to say, these people may be smart, but dear God, their social development is stunted. They all think they are eighty times smarter than they are; they have virtually no social graces, as a rule, are arrogant, won’t shut up. interrupt other people constantly to insert their (often wrong) pearls of wisdom, and are generally a pain in the ass to be around. They do mate with each other occasionally because no one else will have them, but in a colony of nothing but Mensans, everybody would be dead within a week. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [August 14, 2012, 9:45pm UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/65 "2012-08-14T21:45:24Z")
> [@greenslime1951](#): > > I have one unscientific support for this idea: I have visited Los Alamos, New Mexico several times. The population consists largely of the descendants of Manhattan Project scientists–supposedly then and now, the highest proportion of PhDs in any American town or city. Those people are very, very, smart, taken as a group. You can tell by talking to any random person or group of people. I played bridge in the local club, for example, and _everyone_ played at expert level. This is very odd. The children of PhDs in physics aren’t all that likely to get PhDs in physics, and thus wouldn’t be working at Los Alamos. Second, why would they stay? Third, you have not demonstrated correlation between high intelligence and expert bridge playing. Perhaps the people you played with selected themselves for being good, and most of the genius population are whatever the bridge equivalent of potzers? I’ve played bridge at MIT and Bell Labs, for fun, and I assure you we were nothing special. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 14, 2012, 11:24pm UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/66 "2012-08-14T23:24:31Z")
> [@greenslime1951](#): > > I can only imagine with horror a society made up of Mensa members. … Mensa membership however does not represent the premise very well. None of the very smartest people I have met have been Mensans; they feel no need to join such a group. Joining Mensa selects for those who also have some other need in their life that is not otherwise being met. ---
**Author:** ![Damuri\_Ajashi](https://avatars.discourse-cdn.com/v4/letter/d/898d66/32.png) [@Damuri\_Ajashi](https://boards.straightdope.com/u/Damuri_Ajashi)\ **Post date:** [August 15, 2012, 12:24am UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/67 "2012-08-15T00:24:55Z")
> [@Sunspace](#): > > Another crazy idea that occurred as I was watching the closing ceremonies of the Olympics this evening. > > I was looking at all those young healthy faces, and had in the back of my mind the news reports of [the Olympic Village being a total makeout pit](http://www.cracked.com/article_19733_5-things-they-dont-want-you-to-know-about-olympics.html), thus ensuring the next generation of athletes. > > What would happen if we took a few hundred thousand people from the top 1% of humanity and isolated them to start a new colony? > > Let’s say, Mensa members, Olympic athletes, rich people who have earned it themselves, social geniuses… all people who drew genetic winning cards and either grew up in environments where they flourished or had the strength to overcome their non-flourishing environments. > > They interbreed with each other and the generations pass. Would the total population remain smarter, stronger, etc than the average of the people they left behind? This sounds like a James Bond movie ---
**Author:** ![Sitnam](https://avatars.discourse-cdn.com/v4/letter/s/6a8cbe/32.png) [@Sitnam](https://boards.straightdope.com/u/Sitnam)\ **Post date:** [August 15, 2012, 2:32am UTC](https://boards.straightdope.com/t/select-only-smart-people-for-a-colony-do-their-descendants-remain-smart/631341/68 "2012-08-15T02:32:10Z")
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