Skepticism

Only Stupid People Are Breeding?

A few weeks back, a coworker asked my opinion on the idea that humanity might be breeding itself stupider, due to the types of people choosing not to procreate. We had an interesting, if brief, discussion, and I thought it was a topic worth writing about. When, a few days later, the Guardian ran an article by Julian Baggini on the merits of childlessness, and the increasing number of people not having children, I started doing research and organizing my thoughts on the matter to share with you all. Well, it all got pushed a bit to the side, due to my crazy work schedule and everything else, and I’m finally getting back to it now.

This idea seems fairly common. As I processed my thoughts on the matter, I was walking around for an entire week with a line from that Harvey Danger song – you know the one – on repeat:

Been around the world and found
that only stupid people are breeding
the cretins cloning and feeding
and I don’t even own a TV

The whole argument immediately strikes me as incredibly arrogant. The assumption underlying the entire thing is that the people making the argument are the right kind of smart, and that any evolutionary tendency, real or perceived, away from that kind of smart is bad for humanity. A quick google search on the topic yielded all sorts of blog discussions; what I gleaned from a quick scan was a lot of racism veiled in evolutionary language. Most of the research on the topic appears to be based on IQ scores, and many of the bloggers and commenters seem to be suggesting, in subtle and not so subtle ways, that eugenics is probably a good idea.

The thing is, it is difficult to impossible to quantify intelligence. The IQ scale measures a few narrow areas, but it is biased, and tells us very little beyond a subject’s ability to take tests. A major problem lies in the conflation of education and intelligence. Highly educated people are the group most likely to forego reproduction. Yes, most educated people are intelligent, but people making this argument seem to overlook the many smart and resourceful people who, through various circumstances, have not had the time or opportunity to pursue higher levels of education. My parents, a construction worker and a farmer’s daughter, fit this category. There are plenty of smart people out there, living “normal” lives and having kids.

Another thing that strikes me about this is the fact that real genius tends to come at us out of left field. Oftentimes it takes a person with the ability to think beyond the conventional wisdom on a topic to come up with a true breakthrough. Specialized education by definition narrows our vision. This has obvious benefits, but sometimes a person with a broader field of view can pick up on something that may have been staring the experts in the face all along. Also, it seems there may be something to the idea that genius and craziness can be one and the same.

Beyond all that, there is this idea that a lot of people have that we are “devolving”. Anyone with an understanding of evolution should know that there really is no such thing. Evolution has no goal or purpose beyond survival and reproduction. All life is in a constant state of evolution; it reacts to selective pressures to preserve genes for traits that ensure survival and reproductive success. It doesn’t necessarily move toward greater complexity or sophistication, and most of the time it is completely imperceptible at the surface level.

We humans have changed our environment in many ways to enable greater survival. This means that we are subjected to different selective pressures today than we were, say, a few centuries ago. Some see this as a bad thing; fewer of the “weak” are being weeded out, and our populations are becoming “polluted” by inferior genetic material. I think it’s a mistake to try to ascribe value to what natural selection may or may not favor. It’s arrogant to assume that we have any idea what qualities will be necessary and/or beneficial in the future. As the way we live changes, so does what it takes to survive.

It’s difficult to see the ways humanity is being shaped in the moment, or even over a century, but I think it’s safe to say that evolution will continue to do what it does, and we’ll be just fine without implementing a geek breeding program. Although, it occurs to me, isn’t that really what the internet is for? Think about it: the internet is enabling nerds the world over to meet and potentially mate. That has to make up for some of the supposed lack of smart breeders. I’d like to see that study.

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69 Comments

  1. Hi there!

    I agree with most of what you said. You look at the young people and the vast majority of them just seem … stupid. But I challenge any “smart” person to send a text message to their professor while watching Stephen Colbert, listening to Paramore and running a 20-person raid through Zul’Gurub all at the same time. A lot of younger people can do this kind of thing with little distraction.

    This comic sums it up pretty well: http://badgods.com/primitive.html

  2. I agree that this is mostly racist nonsense, but there is one thread of this conversation that has some merit. If you change the frame away from the choices of individuals to more structural concerns, a real problem does emerge. The working conditions of high achievers both inside the academy and in the private sector are newly hostile to having children. The newness is due to the combined effects of women’s increased labor force participation over the last 50 years and the lack of accommodation in the workplace to make room for having children – in fact, workplaces are more demanding of workers’ time than ever.

    While I don’t agree that this is going to cause a major meltdown in evolutionary gain, I think it is worthwhile to think of policy changes that could address this major strain put on workers and families.

  3. @Draconius: love the comic. very appropriate.

    @fetner: i can’t argue with you on that one. though i think it is a solvable problem, and one that will be addressed. as you say, it is a rather recent development, and i think we are just beginning to see it as a problem.

  4. I think the more common effect of certain categories of people choosing not to have kids isn’t a genetic dumbing down of the species, but a dilution of philosophical/educational/ideas as the religious sector is more likely to have more kids (and kids are more likely to share their parent’s beliefs)

  5. I had to put up with this nonsense from my ex. He told me it was important for the “smart, productive citizens like us” to make sure we had as many kids as possible to combat the rising tide of “useless drains on the welfare system.”
    I told him it is my opinion that it’s irresponsible to the Earth to have more than two, one to replace each parent, and that just having one was better. Population-wise, you know.
    (Apologies to parents of 3+ out there, this is not meant personally…)

    Need I mention he’s a conservative Republican? Oh, what a sad mistake I made…

    He had no intention of actually doing the work of raising a child, though, so we had only one. But his brothers and sisters have produced 28 total…

  6. I agree with CharlesP, I think…consider this: there are people that are “in a good place” for breeding (eg, financially and emotionally stable, good support network, an understanding of what’s involved, etc.) and those that are not. Intelligent people should be able to gauge this “good place” and stupid people will likely not.

    So, more stupid are having kids when they’re not ready to. And without arguing about intelligence being passed on, certainly beliefs are – most people who are currently religious will say it’s because they were raised that way (not b/c they gave it careful consideration and then chose). I bet beliefs about quack medicine, etc., follow that suit.

    This is not “devolving”, per se, but I do think we’re heading towards a society where more dumb people are having kids than smart people, and I think that dumb (and hence, too often, credulous) parents tend to raise dumb kids. And as a result, the dumb people are going to continue to outnumber the smart ones.

  7. I am the second of 7 kids. Both parents barely made it out of high school – my dad didn’t complete high school until 25 years after he was to graduate. Neither could ever really be considered smart, although they were creative. All of this meant I grew up slightly above the poverty level.

    I am the only one with a college education and a somewhat prosperous career. I am also the only one to never have kids. The two other siblings to graduate high school each have one child. The others all have large families; both they and their kids are dumb as dirt. This same situation is found in all my relatives – the better educated have one or two children who go on to achieve higher educations; the rest crap out a bunch of kids who are uneducated and can’t get jobs. So within my own family there is a correlation between being educated (smart) and the number of kids.

    My personal philosophy on kids is they should never outnumber the parents.

  8. There’s probably at least SOME genetic component to intelligence. And if you take two people who are already below average inteligence, there’s probably no way their kids are going to be “smarter” than they are, let alone smarter than average. Add to that the educational component, and it seems unlikely they’ll be able to consciously provide the right environment for raising their kids to stimulate intelligence.

    Of course, the main question then becomes: are the people who are, right now, having too many kids the ones who are “below average intelligence”?
    If nothing erlse, they are at least indoctrinating their many kids with their point of view, whether that viewpoint is mistaken or not.

  9. @cypressgreen: You know, that really points out that the main concern of people worried about the quality of human stock is “there aren’t enough people like me,” whether they are eugenicists or the breeding program folks.

    I have no children myself because I don’t want to deal with children. I see no need to present this as proof of my moral superiority.

    If people are that worried about increasing levels of stupidity, education would be a much more direct and useful solution. Evolution is too dependent on environment and thus too much of a crap shoot for us to pretend that we can have any control.

  10. This belief seems surprisingly popular, it’s been my position for a few years now that (at least at this stage) I don’t want any children, and I’ve lost count of the number of people that have told me I should because ‘smart people like you need to have kids’ and that the poor/stupid/whatever would outbreed ‘us’. I tend to think that position is a combination of racism, classist attitudes and ignorance of the implications of the statement.

    There may be legitimacy to the idea that it can, in some instances, it can be harmful to have children too young, before you have a developed knowledge and understanding of the world to pass on to your children. I don’t believe I’ve seen any data to support the idea that there is a genetic basis for any such concerns, so I would think any issues could be addressed through education and support for people that have children that aren’t necessarily doing their best by them.

    As far as I can tell, stupidity reaches across class and perceived genetic boundaries, so I can’t see how there is any benefit to some people breeding over others.

  11. The hypothesis is not necessarily falsified so much as it vague and muddled, which makes it either worthless or even harmful given the emotionally charged nature of the question.

    Furthermore IQ test scores have risen over the years, but we must discard this evidence too for the very same reason: IQ test do a poor job at evaluating this nebulous concept of intelligence.

    Here is a link to Asimov’s essay on intelligence.

  12. I have a couple objections to the argument if not the conclusion…

    1)although devolution is nonsense, I don’t think it follows that as a sentient technologically advanced species we should want or even allow our evolution to be driven by happenstance. In a historical context and based on our short and ever lonelier position in the evolutionary tree, I’d guess that evolution is much more likely to simply end with our extermination than breed super geeks. I realize the conversation is a loaded one due to previous abuses, but I don’t think it is completely without merit.

    2)I think you might be overestimating the opposition to eugenics in the skeptical community. (as many comments already appear to indicate). And to be fair, if we do not figure out how to populate other planets some form of restricted breeding seems not only inevitable but even the moral choice.

    3)I think the comments indicating a sociological problem which is bigger than the evolutionary one have a good point. My wife works with emotionally disturbed kids and the way the problem repeats itself generation after generation (get pregnant early, drop out, have many kids, rinse, repeat) is very depressing.

  13. Sadly, it appears as though overpopulation is a self-correcting problem. Too many births results in more deaths and then the population shrinks.

    In Africa that self-correcting mechanism mostly manifests itself as famine-war and ignorance-AIDS. In the richer western nations, that manifests itself as unemployment-poverty and peole opting not to have kids because everyone else is already having too many.

    again, it leaves the question who the smart/intelligent people are …

  14. I feel like memetics is missing from this discussion. We have, after all, produced the Internet, which has allowed memes to flourish wildly. And while there’s probably a genetic component to intelligence, there’s also undeniably a memetic one: you can’t learn an idea that you’re never even exposed to. We’ve seen a rise in skepticism and a drop in religiosity just in the past few years, and I think that has nothing to do with genetics and everything to do with a war of ideas.

    Or to put it another way, Randi’s never had kids, but most of us here are like his brain-babies.

  15. I’ve always been amused by the tongue in cheek declaration, and observation: “The total amount of intelligence in the world is a constant. The population is increasing.”

    Do I give it any credibility as an accurate statement? No. I simply find it amusing.

    That said, I do not think that we are breeding ourselves stupid, but that there are certain cultural anti-intellectual movements that have taken hold of segments of the population. If we did not think that this is true, then we would not gather as skeptics to try and combat that anti-intellectualism.

    People are frequently gullible, not stupid. There is a difference. All of us here have learned that critical thinking is a skill that we have to practice, and that there are many, many people who don’t think critically.

    Culture flows in cycles, as different groups make big splashes in humanity’s collective soul-soup, and other groups splash bigger to avoid being overwhelmed.

    It’s nothing to do with genetics, it’s all to do with memetics, as jtradke pointed out.

  16. I find the social argument significantly more compelling than the genetic one. Really, the genetic claim is just an oversimplification of the underlying argument which is approximately:

    “As the (expected) quality of upbringing rises among family groups, the rate of reproduction declines.”

    Difficult to test, but it would seem to apply cross some number of (nonindependant) variables (income, education level, crime rate, school quality, etc.)

    Stating it this way also isolates the base argument from the tacked on racism you will often see in such discussions. People falsely trailing this argument into “this is why there should be less black kids” are those who have already made the assumption that the children of black parrents have a lower expected quality of upbringing. I would also suggest that they have probably made some other, even more abhorrent assumptions, but this is the neccesary one. Regardless, the racism is in the underlying assumption, not in the social/evolutionary argument.

    Whether this works across the dimension of religious affiliation is left as an excercise to the reader.

  17. So my husband and I are about 95% sure we’re not having kids. Partially due to medical risk, partially due to our combined personalities and personal choice on the matter.

    But invariably, someone will say “But you’d have such nice, smart kids.” (We are both considered to be insanely intelligent – and we both agree that that and $3.50 buys us a cup of Starbucks, which makes the Starbucks founder far more brilliant than either of us.)

    I feel like just grabbing them and banging their head against a wall. Genetics doesn’t guarantee intelligence. I have some brilliant friends with parents of average intelligence (though usually of well above average ambition), and I have some friends who are brilliant who have smart kids, but nowhere near brilliant.

  18. @jtradke:

    Does that mean I have two daddies and a mommy? Brilliant.

    @Zapski:

    “Culture flows in cycles” is something I can definitely agree with. However, cycles can be broken, and we can never underestimate the power of anti-intellectual movements and other such movements that are a threat to the well-being not just of future generations, but of our own generation. In the grand scheme of things, I’m just a grain of sand, and perhaps the duration of such movements is comparatively short, but I like me, and don’t want to live in a theocracy (or any other sort of abusive government, but that’s an example).

    It’s also regional. We may be thinking in huge strokes here. There are places that are pro-intellectual, progressive, and seem to be pretty set on doing things that way. And there are places where they’ve barely risen from despotism and tribalism of the murderous sort. It’s not about that.

    I’m amazed at how a country like the US, where people are given such freedom, seems to have such a large proportion of the population retreating into conservatism that is barely above the racist/discriminatory/manifest destiny behaviors of a couple of centuries ago. You’d think people would want more, not less freedoms.

    I personally intend to have children, but not hordes of them. I want to educate them in such a way that I feel I’ve been a dedicated parent and prepared them to be a positive influence on the world.

    I don’t think it is, as was stated before, an issue of “outbreeding”. I think it’s an issue of “out-educating”, and that is something that the nerds, so to speak, tend to be in a position to do. As the Francis Xavier (a Jesuit) said (and I may be misquoting) “Give me the boy until he is seven, and I’ll give you the man”.

  19. @TheCzech:

    Arg, that reminds me of one of the most embarrassing moments of my life. While we were in a Indian restaurant, my mother was bemoaning my decision not to have children, and said in front of an Indian staff member that ‘we should have kids as we are being out bred by the Indians’

  20. @namidim: “1)although devolution is nonsense, I don’t think it follows that as a sentient technologically advanced species we should want or even allow our evolution to be driven by happenstance”

    Evolution is two parts – variation and selection. Variation is happenstance, from our perspective. So, the only way we could “guide” our evolution is select who gets to breed. That would be a tough sell – who gets to decide?

    Also, your point about populating other planets to prevent overpopulation here – that doesn’t really address the issue, unless you are talking about moving billions of people from one planet to another (prohibitively expensive). For example, if we were to colonize Mars, with any amount of people, that would not stop the billions left behind on Earth from breeding.

  21. @exarch: Sadly, that’s the way evolution is supposed to work. more offspring than resources = competition = selection. Sadder yet, when your offspring mature, you are their competition as well.

    I always say, evolution is undeniably true, but it also undeniably sucks.

  22. Intelligence has been proven over and over again by solid scientific research to be substantially an artifact of inherited genetics with environmental factors being of minor influence. Also two not so smart people can often have a smarter child in the same way that two very intelligent people often have a child who is not as smart as the two parents. This observable and established statistical phenomenon is called regression to the mean.

    Also IQ testing is a well established science used to determine basic capacities and to establish where a certain individual falls on a comparative scale in relation to everyone else who’s taken the test. To say it only measures ones ability to take a test is in fact a myth. IQ testing has been shown to be a strong indicator of parental intelligence as well as predicting a person’s capacity and likelihood of success in many life functions. This is not social politics, its science. There certainly are many social factors that can influence ones individual success, but IQ is a very good indicator of how successful someone is likely to be in school and at work in comparison to others. And anecdotal exceptions do not invalidate decades of repeated scientific research.

  23. I’m torn because on the one hand, I agree that the argument is appalling on a number of levels, but on the other hand, the irony of the idiots decrying the excessive breeding of other idiots is pretty awesome.

    I usually point out that environment is also a critical factor for “intelligence” (whatever you mean by that), and that our environment has, by and large, dramatically improved over the last few hundred years, and continues to do so.

    Well, except for the natural environment — as Randall Munroe pointed out, we’ve already fucked that up.

  24. This is not about evolution. That would take more like 100,000 years to see a change. It is about social learning. So stop worrying about breeding programs, it won’t change anything about the human brain’s ability to adapt and learn. Education is the key here, especially those of females around the world.

  25. @cypressgreen:

    I told him it is my opinion that it’s irresponsible to the Earth to have more than two, one to replace each parent, and that just having one was better. Population-wise, you know.

    The trouble being that that argument only succeeds in reducing the population of people responsive to that argument.

    No, I don’t have a better solution.

  26. @frisbeetarian:

    In terms of evolution, it would be interesting to find some people who have kids because they are too stupid to be able to use birth control correctly, regardless of their belief system. I’m pretty sure they are out there. Then, observe if this trait is passed on to their children, and how many grandchildren they have compared to the average.

    If there is anything to this, it should take less time to see the results than other multi-generational human genetics studies.

  27. The socio/environmental problem (not the evolution/IQ bunkery that has been correctly poked to death here and elsewhere) is a fairly interesting political test.

    If you accept the core hypothesis (Higher quality child rearing environments lead to, or at least correlate with, lower reproduction) then you’ve really only got two levers to move:

    1. Attempt to modify environmental quality at the low end of the spectrum, thus lowering the correlation. This is done through, as mentioned, education, community rennovation, arts funding, progressive taxation, etc. Generally, causes associated with the left.

    2. Attempt to lower the birth rate in lower quality environments (the defenition of which is where all the isms creep in) or raise its converse. This can most easily be accomplished by making having children more expensive (by all defenitions of the word) at one end and more lucrative at the other end. Generally, this leads to reducing childcare tax credits, cutting school lunch and suchlike programs, lower community development funding and the privatization of education, causes which are equally well associated with the political right.

  28. @Draconius:

    This comic sums it up pretty well: http://badgods.com/primitive.html

    I wouldn’t be at all surprised if humans had to be more intelligent–for some measurement of intelligence–when they had to take more responsibility for their own survival, and when there was no safety net to prevent you from being killed by your own stupidity. (Consider those kids who stood on the rail of the tiger enclosure at the zoo and taunted the tiger–how long would they have survived in the stone age?)

    Domesticated animals tend to be stupider than their wild equivalents–supposedly wildcats have one third more brain cells than their domestic descendants, and dogs are developmentally retarded wolves–they never grow up, mentally. In some ways, humans have become a “domesticated species” with the development of agriculture, if not earlier.

  29. they say (dawkins, etc.) that the true winners of the evolutionary competition are the genes that manage to reproduce…so i’d say those who are reproducing successfully, and more often, are the ones who are “winning” at evolution.

    so perhaps being “too smart for breeding” is acutally an evolutionary handicap?

    *this is meant to be a bit tounge-in-cheek, FYI. don’t flame me.

  30. @SKrap: Or, as was mentioned above, we can make the work environments of those who are well-educated/high IQ’d/successfully employed more accomodating to family life, and thus not have to go the political route at all…simple steps like allowing flex time, encouragement of telecommuting, at-work child-care programs, longer maternity and paternity leave, etc. are all things practiced in other countries that do not have debates such as this (I’m thinking Scandanavia as one example).

  31. I’d worry about it if sex drives were linked to intelligence. But happily, we all love sex! And given that birth control is not 100% successful, and many people choose to keep even the most unintended of preganancies, we should remain happy f*ckers unless we destroy the planet first.

    This is a silly issue to argue. Early childhood interventions as simple as preschool can help far more and far more simply than any kind of eugenics program, particularly if targeted to areas with high poverty levels, where kids are less likely to have a stimulating home environment.

    And HUGE kudos to those parents who create stimulating environments despite resource constraints. Huge.

  32. I think it seems like that, but it’s just another guilt-ply people use to try to convince others to live according to their personal belief systems…
    “But you HAVE to have kids! Otherwise the Jews/ Chinese/ Fairies/ Gnomes/ whatevers will take over the world!!!”
    Bleh. Fine. Let it be so. Doesn’t bother me. Besides, my sister-in-law had four kids and she’s kinda smart, so I rely on her to pass on whatever gnome-y wisdom my husband might have. ;-) Although I do remind her that she’s four times as old as I am -since you’re only as old as how many kids you have. ;-)

  33. I think it’s inherently stupid to have ANY children (let alone multiple) that you can’t afford to take care of when you’re living in a first world nation with all kinds of information and contraception available.

  34. @Baroncognito:
    Exarch, what support do you have to claim that two people of below average intelligence won’t be able to have a child that is more intelligent than they are?

    I didn’t say they weren’t able to, I said it was unlikely.

  35. @Draconius: Actually, a lot of younger people are fooling themselves into thinking they can do multiple tasks at once. So far most studies into multi tasking have shown that we can’t do it. We seem to only be able to do one task at a time. When we try to multi task either all of the tasks suffer or we pay attention to one task at a time and ignore the others.

  36. @James Fox:

    Intelligence has been proven over and over again by solid scientific research to be substantially an artifact of inherited genetics with environmental factors being of minor influence.

    This may be true for an individual, but that doesn’t preclude a general upwards trend for the whole (as evidenced by e.g. the Flynn effect). Regression to the mean is of course important to consider, but that IQ seems to regress to an ever-increasing mean needs an explanation as well.

  37. I think there’s a confusion here between “stupid” and “ignorant”. One can be either or both, but “ignorant” is curable. It’s the ignorant out-breeding the educated that becomes a problem, not the stupid out-breeding the intelligent.

    There are also factors that can negatively affect natal outcome: lack of pre-natal care, diet of the mother, drug and alcohol consumption, smoking, etc., and post-natal problems such as inadequate nutrition, or lack of interaction leading to failure-to-thrive syndrome. These tend to be socio-economically driven and those same socio-economic factors tend to preclude the resultant children getting appropriate care for any problems. The cycle self-perpetuates,

    Take my Offspring, who does not actually share any of my genes. He is adopted, born in Korea to a teenager who received no pre-natal care. Despite the fact that he started reading aloud at 18 months [Mommy reading to him/ Sesame Street may have helped] and was adding and subtracting at age two [definitely the Sesame Street computer game], he has a reading/aural disability related to word-senses that affects his comprehension. [He also had some fine-motor control problems he’s outgrown.] He had been assessed as a pre-schooler as “highly gifted”, but when he switched schools in fifth grade, the teacher opined that he was “slow”. Had he not had highly-educated parents who were perfectly willing to take on the school system to see that he got the assistance and accommodations he needed, who made sure he got therapy, and who convinced him that his learning problems did not mean he was “stupid”, I expect he would have lived up [down?] to the expectations of his fifth grade teacher, rather than growing up to graduate college with honours.

    Had he been child #7 in a low-income, low-education family, his native intelligence coupled with a low sense of self-esteem – who knows how he would have ended up? Career criminal or just a guy at the 7/11 who could make correct change in his head?

    In the interests of brevity, I will not now go into a rant about improving the quality of teachers in the public school system, providing every student with adequate breakfast/lunch nutrition and making “abstinence only” sex-ed illegal…

  38. @exarch:

    @Baroncognito:
    > “Exarch, what support do you have to claim that two people of below average intelligence won’t be able to have a child that is more intelligent than they are?”

    I didn’t say they weren’t able to, I said it was unlikely. <

    And you're wrong to say so. Because of regression to the mean, the IQ of children of two low-IQ parents is likely to be higher than that of either parent.

  39. As others have mentioned, culture plays a more important part here on the time scales we can grasp. Currently, people who disagree with me are having more kids on average than people who agree with me. Personally I think the people who agree with me should have more kids, but if their urge to reproduce is so low, it’s a good thing they’re out of the gene pool, and hopefully they’ll stay out of the meme pool as well.

  40. @lemsroberts: I would argue that those are sociopolitical changes, as they are unlikely to take place within a plurality of large companies without outside pressure.

    Nonetheless, that half of the environmental change lever was a clear omission from my analysis. (1) should have been expanded to include both types of environmental change.

  41. @jtradke: There are some interesting aspects to the Flynn effect in that it has only identified the upward trend with those with lower IQ scores almost exclusively. There is a strong argument that improved diet, better health care, less incest, and all that sort of stuff makes improvement more of a raise to the potential of those most adversely effected by environmental or negative genetic factors. From what I’ve read the above average and smart people do not seem to be getting smarter.

    @AndrewBarton: There is definitely a history of controversy with this issue but the most interesting aspect of heritability is that after leaving adolescence and going into adulthood the indications of heritability of intelligence is confirmed to a greater degree.

    The wiki article http://en.wikipedia.org/wiki/Heritability_of_IQ gives a good explanation, provides citations and states:

    “The mean correlation of IQ scores between monozygotic twins was 0.86, between siblings, 0.47, between half-siblings, 0.31, and between cousins, 0.15. From such data the heritability of IQ was estimated at anywhere between 0.40 and 0.80 in the United States. The reason for this wide margin appeared to be that the heritability of IQ rises through childhood and adolescence, peaking at 0.68 and 0.78 in adults, leaving the overwhelming majority of IQ differences between individuals to be explained genetically

    and

    “According to work by Robert Plomin,heritability estimates calculated on infant samples are as low as 20%, rising to around 40% in middle childhood, and ultimately as high as 80% in adult samples in the United States.[14] This suggests that the underlying genes actually express themselves by affecting a person’s predisposition to build, learn, and develop mental abilities throughout the lifespan”

  42. Is there room for some dolphin/homosapien lovin’ in all this? Maybe we need to breed humans out altogether they haven’t been hugely helpful to the planet…..Evolution: “This species sucks!”…next!

  43. @Gabrielbrawley: Nope, I’m not calling anyone stupid – I’m calling peoples’ actions stupid. If you can’t afford to reasonably take care of a kid, you shouldn’t have one (or four).

    Maybe I should change that to “flagrantly irresponsible”. From what I’ve gathered by what you’ve shared, though, you seem to be an engaged parent who takes fine care of his kids…but that’s only what I’ve gathered from what you’ve shared.

  44. @DataJack
    1)Variation isn’t going to be beyond our control for very long. As far as selection goes you could, for instance, mandate that a woman could have no more than 2 children. That would certainly reduce the ability of any particular group to outproduce another and wouldn’t be particularly unfair (assuming which brings me to

    2)Well this is my point. We’ll have to breed less. someone will have to decide who gets to have how many children at that point as well, fair or not.

  45. *tosses out bait*

    On the other hand, one of the arguments on why the Neanderthal died out is that heads got too large. Perhaps stupidity, so long as intelligence remains above a certain level, is an evolutionary advantage?

  46. Yes, Idiocracy: http://xkcd.com/603/

    Stupid people aren’t reproducing any more than ever. It does seem that there are more people going for the childfree lifestyle, but in my personal experience (yes, it’s anecdotal), the people who choose to be childfree aren’t necessarily any smarter than those who don’t.

    It also doesn’t seem like there is any sort of increase in people believing in ridiculous crap. People have believed in Astrology, quack medicine, the paranormal, etc. for a very long time. This isn’t likely to change. If anything, as science and technology continue to advance, there are more people who are openly rational and skeptical. We live in a culture where people are becoming increasingly open to science and reason, and I think this is a good thing.

  47. I very much doubt I will ever have children, if for no other reason than I can’t stand the little buggers.

    Another point to make is that natural selection is not far from becoming obsolete for humans. I’d be very surprised if natural section was still more important than artificial selection to our genome in 100 years (a blink of the eye in evolutionary terms) and I’d be very disappointed if humanity was stuck with our low level of intelligence in 100 years.

  48. @James Fox:
    The first thing I’d say about IQ/intelligence heritability studies is that differences in intelligence are only more attributable to genetics as more environmental variables are held constant, i.e. having access to clean and abundant food and water, medical care, etc. To say that the biggest influence on intelligence is genetics is silly — just ask a 25 year old feral child (http://en.wikipedia.org/wiki/Feral_children).

    As a biologist, my biggest concerns with these debates, and with the IQ/intelligence heritability studies, are about the often narrow definition of intelligence.

    It’s often said that “there are many types of intelligence.” This makes sense biologically. A basic fact of biology to remember is that a specific gene makes a single protein. If there’s one thing we can sure of, it is that there are many, many, many genes involved in constructing the human brain, and they are programmed to respond in all sorts of ways to the outside environment. I’m sure there are genes that contribute to our ability to store memories better, or manipulate 3-d objects in our head more easily, and all sorts of generally desirable traits. I also bet there are some that provide something beneficial at the cost of something negative, like simultaneously making us better concentrators on a particular task but more forgetful. The bottom line is that, as far as my understanding of biology goes, no one set of genes is going to make somebody good at everything. Nor is a 10% lower efficiency at processing a particular speech pattern going to prohibit someone from being a brilliant scientist or understanding that religions are probably fabricated.

    Does it really make any sense that most of our cognitive capacities would differ in incredibly meaningful amounts, given the enormous selective pressure there must have been for us to develop such finely tuned brains to begin with? Our genetics are definitely variable, and probably set the upper and lower limits on a lot of traits. However, I think it’s going a bit too far to make specific claims about a genetic division that classifies the lower rungs of society as “stupid” and those who do the best in American school as “intelligent.”

  49. I guess a lot of people don’t realize that Idiocracy is fiction. Yeah, I’ve watched the movie and there are a lot of flows with the “logic” in it. Most importantly, intelligence is only partially hereditary. Education is extremely important, and that’s not genetic at all. This is why it’s a good investment to spend money for education for those who can’t afford it. This is also why I’m not as scared as the Duggars as I might otherwise be. They’ve done a pretty good job of isolating and controlling their 20-ish kids, but that can’t work in the long term. Some of the kids will rebel and get a real education, or at least some of the kid’s kids will get a real education.

    Second (and more importantly), apparently the “stupid” people have been outbreeding the smart ones for decades, and yet IQ scores continue to rise in spite of this. Evidence, people.

  50. @AndrewBarton:
    And you’re wrong to say so. Because of regression to the mean, the IQ of children of two low-IQ parents is likely to be higher than that of either parent.

    Seeing how my slightly tongue in cheek comment is now being taken dead serious here (I was in fact mostly saying that it was unlikely that two below average parents would have an above average child), I suppose it’s about time to play the same game back.

    Please show me anything that proves that as far as IQ goes, 0.9 plus 0.9 divided by 2 equals more than 0.9.
    For starters, the IQ number expresses the distance FROM the mean (the mean being 100). Or more precisely, it measures how many years ahead (or behind) you score. Which means that as people get older, that difference gets smaller (2 years ahead being much more significant for a 6 year old than for a 60 year old person).

    In other words, as your parents get older, even if they have a below average IQ, the number will still creep closer to 100 as they age.

    So I restate:
    it’s unlikely that a below average child will score higher than their parents.

    Regression to the mean is a population phenomenon, not an individual phenomenon.

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