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October 19, 2013 / JayMan

Apples, Oranges, and Lesbians: The Nurture Assumption Just Will Not Die

shutterstock_29040811625x415A new study (recently discussed by Steve Sailer) has found that the children of gay and lesbian parents have a lower high school graduation rate than those of straight parents.

The finding of this study seems straightforward – indeed, I was able to say it in a sentence. However, the conclusions we are able to draw from these finding are anything but.

The study looked at sample of 20% of the individuals in the 2006 Canadian census. Unlike previous studies, it has the strength of being able to examine a large, truly random sample.

Previous studies into the matter have claimed to find no significant differences between the children of gay and parents vs. those of straight parents. However, those studies apparently suffered from serious methodological weaknesses. The author of the current study explains:

Generally speaking the literature is characterized by several different types of data bias and small samples that lack any power … Although a proper probability sample is a necessary condition for making any claim about an unknown population, within the same-sex parenting literature researchers have studied only those community members who are convenient to study … Of the fifty-three studies reviewed here, only seven used probability samples. All of the other studies arrived at their samples through means that introduced various levels of bias. Some studies recruited individuals from sperm bank data sources or other types of reproduction technology providers. Other studies used Internet surveys where the respondents were recruited by various methods: parent forums, gay and lesbian web-sites, and online advocacy organizations. Many studies recruited through LGBT events, bookstore and newspaper advertisements, word of mouth, networking, and youth groups. A common method of recruitment was to use a combination of the above methods to form a sample base, and then recruit friends of the base. Still other studies failed to even mention how their samples were arrived at. Each different procedure has a different and unknown source of bias.

Aside from the problem of non-random samples, most of the existing parenting studies contain tiny sample sizes. Of the fifty-three studies examined here, only two had sample sizes larger than 500. Much more common were sample sizes between 30-60. The problem with such small sample sizes is that the data cannot generate any power for statistical testing, and low power means there is a small chance of rejecting a false null hypothesis. Hence, the very small sample sizes found in many of these studies creates a bias towards accepting a null hypothesis of ‘‘no effect’’ in child outcomes between same-and opposite-sex households.

OK, so this study “corrects” for these shortcomings by relying on a large, random sample. Still, the rarity of same-sex couples meant that there were few in the sample. Indeed, there are apparently only 423 gay and 969 lesbian families in the entire nation of Canada. Nonetheless, its sample is larger than most such studies.

The study found that children with lesbian “parents” were only 60% as likely to graduate from high school (sons 76%, daughters 45%), while children with gay male “parents” were only 69% as likely (daughters 15%, sons 161%). The disparity remained significant even when certain controls were introduced (such as parental education).

So case closed, right? We can now safely conclude that two opposite-sex parents are important for children’s development, yes? Of course not, not even close.

First of all, despite this study’s improvements over its antecedents, it suffers from a fundamental weakness. It is in essence a classic family study, one that looked at associations within families and then emboldens others to draw conclusions (as illustrated by the title “A Married Mom and Dad Really Do Matter: New Evidence from Canada”) about “family constellation variables.” Yup, there’s your problem: classic confusion of correlation with causation.

You can’t make causal determinations from standard family studies. Even with heterosexual parents, finding associations between parents and their biological children tells you nothing about whether anything about the parents’ rearing of the children had anything to do with what you find, not for the least reason being heredity. Just as finding that substance abusing parents have children that go on to do the same, heredity confounds you at every turn. This is because, as readers should know by now, all human behavioral traits are heritable.

Hence, a key problem is that comparing gay/lesbian parents to straight parents – even when you put in your “controls” – is essentially comparing apples to oranges. I don’t have to tell you that gays and lesbians – particularly the ones that try to live in married/civil union couples are systematically different from straight individuals. A passage from the study illustrates this point:

in the context of gay parenting … avenues through which these households are formed are many and complicated. As noted by Stacey and Biblarz … these families often have experienced a prior divorce, previous heterosexual marriages, intentional pregnancies, co-parenting, donor insemination, adoption, and surragacy.

The biological children of gay and lesbians can hardly considered to be genetically comparable to those of straight individuals, even discounting the sexual orientation itself.

That’s if they’re even their biological children. Here’s another finding of the study:

There are a higher number of visible minority children for gay households (28 % compared to 13 % for common law couples), and a higher number of disabled children (13 % compared to 6 % for opposite sex married parents). This may imply a high number of adopted children in gay households, but interestingly there are no cases of inter-racial same-sex families within the 20 % sample.

I don’t even need to touch the higher fraction of “visible minority” and disabled children in the same-sex parent sample. That’s just icing on the cake at this point.

Having same-sex parents, in and of itself, likely has no impact on children’s development. It would be really strange that if it did, since parenting in general (across the broad range that constitutes “normal” parenting) has no impact on how children turn out. That was the revelation in my first blog post, and it’s a fact that remains underappreciated to this day. This study of gay parents doesn’t change our understanding.

The failure to recognize the broad null effect of nurture (“The Nurture Assumption) is pervasive even in the HBD community, the people who should of all know better.

Indeed, a recent blog post reciting some quips from Robert Plomin (a foremost behavioral geneticist) rekindled a discredited idea to explain the consistent non-effect of the shared environment term (the fact that there is no correlation between children raised together once you take genes into account) (emphasis in original):

In short, parents think they treat their kids the same… but the kids think the parents treat them differently, and outside observations would support this claim. If anything, the outside observer sees slightly more unequal treatment than the kids themselves do. This indicates that the vast majority of parenting effects would show up in the non-shared environment.

That said, modern study designs have indeed allowed us to decompose the known sources of non-shared environmental influences. Here is the relevant data from the paper:

The proportion of total variance accounted for in outcomes such as adjustment, personality and cognition was 0.01 for family constellation, 0.02 for differential parental behaviour, 0.02 for differential sibling interaction and 0.05 for differential peer or teacher interaction. Moreover, these effects are largely independent and they add up to account for 13% of the total variance. If non-shared environment accounts for ~40% of the variance in these domains, we could say the cup is already more than one quarter full.

Parent-child interaction was the Occam’s Butterknife way for developmental psychologists to rescue parenting after studies failed to turn up evidence for its effects. Judith Rich Harris and Steven Pinker both long since dispatched this idea, as I explained:

It requires that there are no across the board differences from one set of parents to another. To see why, imagine parents did have some effect. Even if there were differences in the exact treatment each child received, there are going to be systematic similarities with the way each set of parents treat all their children. If such an effect existed, it would turn up in the shared environment, since kids growing up together would be impacted by these across the board similarities. But the shared environment influence is in fact negligible.

It requires perfect crossover interaction. Let’s say you assume that parental effects – whatever their across the board similarity for a given set of parents – had totally idiosyncratic effects on children. Then in order to explain the null effect of the shared environment, the sum of these effects on children’s traits had to be exactly zero. Any number of children exhibiting one sort of effect would have to be balanced by an equal number of children exhibiting the exact opposite effect. That is a rather large stretch.

Occam’s razor and….

The notion that parental influences exist, but the factors that vary among parents in how they treat their children across the board must either have no consistent effect or must perfectly cancel across children such that it gives the appearance in the data that it has no effect at all requires us to entertain many more causal entities that the simpler idea that they just have no effect at all.

Of course, it gets worse for parenting, thanks to studies into the effects of birth order:

In any case, there is additional trouble for the idea of significant parental impact: it has to contend with the absence of birth order effects. Thorough analysis has failed to find any systematic differences in children due to birth order. Birth order is one case of systematic, non-genetic differences in the home environment of children. It’s hard to reconcile the existence of parental effects with the failure to find anything when looking at a reliable systematic difference in the parental environment.

Parenting is simply less important than most people think. But as with the issue with health and obesity, even individuals who understand the pervasiveness of nature and  the apparent stochasticity of what we call “environment” like to believe there is some way they can exert control (see locus of control, courtesy Richard Harper).

To be fair to parenting, over at my comment at the blog I left the current unknowns about parenting:

Now, to be completely fair to parenting, some commenters on the matter, such as Steve Sailer, posit that parental effects are largely unimportant when looking at higher-SES, Western parents. The difference from one set of middle-class Western parents to another set may not matter much, but the difference might matter if we compared White Western parents to say poorer Latin American parents. On that we have to say the data don’t yet rule such a difference out. My own suspicion is that even in those cases, we will find that the difference – if any – stems from environmental impacts that only act in a negative way; e.g., we know that childhood malnourishment can stunt IQ, but nutrition beyond what’s adequate won’t raise IQ. In the same way, children from poorer families might miss out on critical developmental inputs. As well, they may miss out on key opportunities to achieve, which itself is perhaps more a function of the outside the home environment in which these poor children happen to dwell.

Only further research with non-Western, non-White samples can hope to answer this question. In either case, for now, the message is clear, parenting matters a lot less than society merits it, be those parents married, unmarried, straight, gay or lesbian.

As for the song for this post, while this song doesn’t have much to do with the subject, for some reason, it seems to me to fit:

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61 Comments

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  1. redneck01 / Oct 19 2013 6:49 PM

    Having same-sex parents, in and of itself, likely has no impact on children’s development. It would be really strange that if it did, since parenting in general (across the broad range that constitutes “normal” parenting) has no impact on how children turn out. That was the revelation in my first blog post, and it’s a fact that remains underappreciated to this day. This study of gay parents doesn’t change our understanding.

    “Within the range of normal parenting”. Casual and unscientific observation would suggest that gay parenting is seldom normal. Children of lesbians are apt to be starved and beaten, often simply forgotten and ignored for long periods.. Children of gays are apt to be sexually exploited.

    • JayMan / Oct 19 2013 7:36 PM

      @redneck01:

      “Within the range of normal parenting”. Casual and unscientific observation would suggest that gay parenting is seldom normal.

      I knew people would latch on to that point. I mean parents who don’t lock their kids in dark rooms or beat them bloody on a regular basis. Gay parents are within the range of what is “normal” for most parents.

      Children of lesbians are apt to be starved and beaten, often simply forgotten and ignored for long periods.. Children of gays are apt to be sexually exploited.

      Evidence?

    • redneck / Oct 20 2013 12:29 AM

      “casual observation” is what I can see, but not necessarily what you can see. I cannot provide any evidence that you can check that lesbians are apt to simply forget their children for quite long periods and capriciously beat the hell out of them when they remember, but as for gays, one indicator that we can both observe is that the poster boys for gay fatherhood (“Two dads are better than one”) subsequently wound are charged with performing sex acts on their infant and sharing him around. Just as the use of Marie Curie as science poster girl suggests a shortage of science poster girls, the use of Mark and Pete as poster boys for gay dads suggest a shortage of gay dad poster boys.

    • JayMan / Oct 20 2013 12:38 AM

      @redneck:

      I cannot provide any evidence that you can check that lesbians are apt to simply forget their children for quite long periods and capriciously beat the hell out of them when they remember

      Perhaps then you should stop right there?

      You would need a study like the one here to ascertain if these are the case. Since this study didn’t mention it, we have nothing.

    • redneck / Oct 20 2013 1:14 AM

      Thirty or forty years ago, everyone would have simply assumed that a gay or lesbian couple would provide a violently abnormal environment for any children, often a non survivable one, and if anyone was so weird as to suggest the contrary, people doubtless would demand a properly scientific study to prove the contrary.

      But whereas back in those days, it would have been perfectly possible to conduct such a study, today it is entirely impossible.

      Why then should you assume that we are wiser than they. Why should the recent politically correct assumption be the null hypothesis – particularly when it has ceased to be possible to investigate the hypothesis?

      If PC is the null hypothesis, no evidence will ever be sufficient to disprove the null hypothesis – because the bearer of bad news will lose tenure.

    • JayMan / Oct 20 2013 1:21 AM

      @redneck:

      Thirty or forty years ago, everyone would have simply assumed that a gay or lesbian couple would provide a violently abnormal environment for any children, often a non survivable one

      Right, based on nothing.

      Look we don’t assume Santa Claus put the Christmas presents under the tree without some evidence.

      and if anyone was so weird as to suggest the contrary, people doubtless would demand a properly scientific study to prove the contrary.

      The burden of proof rests with the person asserting the claim.

      Look, we need scientific methods to verify any empirical claim. Period.

    • redneck / Oct 20 2013 1:39 AM

      “Right, based on nothing. “

      Based on casual observation. Based on the same application of Mark 1 eyeballs as I have employed, to obtain the same results.

      To deny that sexual deviants are dangerous to children, including their own, is like denying that is dangerous to be white in certain neighborhoods. Those who deny it, nonetheless do not go to those neighborhoods..

    • redneck / Oct 20 2013 4:41 AM

      Look, we need scientific methods to verify /any/ empirical claim. Period.

      Why don’t we need scientific studies to verify the empirical claim that gay and lesbian couples usually provide a childrearing environment within the normal range for heterosexual couples?

      Do we need scientific methods to very the empirical claim that black neighborhoods are usually far more dangerous for whites than white neighborhoods, well outside the normal range for white neighborhoods.

      If so, we are not getting such verification, partly because scientists will not go into those neighborhoods.

    • JayMan / Oct 20 2013 12:32 PM

      @redneck:
      I know most people aren’t trained as scientists or in how to use the scientific method, so they may not understand how we come up with these conclusion.

      The fact of the matter is that the factuality of all claims require evidence to substantiate. Even a claim as plain as “objects fall to the ground when dropped” requires evidence. It’s just that such evidence is easy to obtain; all you have to do is get objects and drop them. More subtle claims may require more sophisticated evidence, which is where science comes into play.

      Why don’t we need scientific studies to verify the empirical claim that gay and lesbian couples usually provide a childrearing environment within the normal range for heterosexual couples?

      You do. Hence, studies like this.

      Do we need scientific methods to very the empirical claim that black neighborhoods are usually far more dangerous for whites than white neighborhoods, well outside the normal range for white neighborhoods.

      Yes.

      Look, this has been adequately explained to you. If you persist with this line of reasoning, I will assume you are trolling and react accordingly.

    • redneck / Oct 20 2013 11:24 PM

      Why don’t we need scientific studies to verify the empirical claim that gay and lesbian couples usually provide a childrearing environment within the normal range for heterosexual couples?

      You do. Hence, studies like this.

      But this study does not support the proposition that the gay and lesbian couples usually provide a childrearing environment within the normal range for heterosexual couples.

      Indeed, it suggests that gay and lesbian couples usually do not provide a childrearing environment within the normal range for heterosexual couples.

      And your reaction is that that implication, an implication that thirty or forty years ago everyone would have thought to be completely obvious and entirely expected, is unthinkable and unscientific, indeed anti scientific, and anyone who persists in that implication is going to be banned.

    • JayMan / Oct 21 2013 8:55 AM

      @redneck:

      But this study does not support the proposition that the gay and lesbian couples usually provide a childrearing environment within the normal range for heterosexual couples.

      The study makes no statement either way. Reread the post.

      And your reaction is that that implication, an implication that thirty or forty years ago everyone would have thought to be completely obvious and entirely expected, is unthinkable and unscientific, indeed anti scientific, and anyone who persists in that implication is going to be banned.

      Pretty much – or at least moderated, because I have little patience for those who preach the gospel.

    • James A. Donald / Oct 21 2013 11:58 AM

      The study makes no statement either way.

      The study was intended to find the effect of gay and lesbian child rearing, relative to the effect of heterosexual childrearing. It found very large effect.

      We know that normal variations in child rearing have very little effect.

      Therefore, a very large effect, indicates an abnormal variation in childrearing, indicates that gay and lesbian childrearing behaviors are usually outside the norm for heterosexual couples.

      Which is what anyone could have told you thirty years ago.

      You would like to find some other explanation of results. Maybe they are all adopting African orphans, resulting in a large genetic difference, but they are not all adopting African orphans, and if they were, would not explain the sex related differences.

      Indeed, back when these children were babies, it was not possible for gays and lesbians to adopt, because everyone knew that gay and lesbian childrearing practices were commonly outside the norm for heterosexual couples, therefore these children are almost always the biological children of one member of the couple. That they have a lower IQ than their parents probably reflects environment, and thirty years ago everyone would have assumed reflects abuse and neglect at physically damaging levels.

      You are explaining the results of the survey away, you are refusing to accept the survey results at face value, because of your prior assumption that gay and lesbian child rearing practices are usually within the normal range for heterosexual couples.

      A prior assumption for which you need no scientific evidence, and you reject any scientific evidence that contradicts it.

    • JayMan / Oct 21 2013 12:12 PM

      @James A. Donald:

      The study was intended to find the effect of gay and lesbian child rearing, relative to the effect of heterosexual childrearing. It found very large effect.

      The study is fundamentally incapable of demonstrating such effect, for the reasons stated. That was the whole point of the post!

      You are explaining the results of the survey away, you are refusing to accept the survey results at face value, because of your prior assumption that gay and lesbian child rearing practices are usually within the normal range for heterosexual couples.

      No, for the reasons stated in the post.

      A prior assumption for which you need no scientific evidence, and you reject any scientific evidence that contradicts it.

      Let me clear it up for you. The only way to reliably study the effects of gay parents (or for that matter, any “family constellation variable”) is with the equivalent of a randomized controlled trial – you need to study adopted children, and then you would have to ensure that there are no systematic differences in the way the children were adopted to the respective homes (in gay vs. straight parents).

      The rest of your post is nonsense.

      Look, I’m tired of recycling these points. Future comments from anyone that ignore the points raised in the post and continue to respew this same broken rubbish you have will be deleted.

    • James A. Donald / Oct 21 2013 4:53 PM

      The only way to reliably study the effects of gay parents (or for that matter, any “family constellation variable”) is with the equivalent of a randomized controlled trial – you need to study adopted children, and then you would have to ensure that there are no systematic differences in the way the children were adopted to the respective homes (in gay vs. straight parents).

      By your standard, there can never be scientific evidence that gay and lesbian child rearing practices are frequently outside the norm. How convenient.

      With an effect as large as this, genetics cannot confound matters significantly. You are not explaining the data, but explaining the data away, and your explanation is weak.

      Secondly, if we apply this self serving standard, the obvious thing to do is to look at the child rearing practices of particular gay and lesbian couples.

      This, of course, is a collection of anecdotes, and suffers from the problem that only spectacularly horrid cases come to our attention, but it is certainly suggestive.

      A controlled look at child rearing practices would work, but such a survey would amount to a dragnet for crimes, looking for crimes without reasonable grounds for suspicion, and thus be a gross invasion of privacy.

      One solution would be a uniform policy of looking for and investigating signs of child abuse – unwashed children showing up at school, hungry children at school, bruised children showing up at school, children with sexually transmitted diseases, self harming behavior at school, and then determine to what extent these symptoms correlated with being raised by gays and lesbians. One could not use the results of the investigations, because you would doubtless argue that the investigators would be influenced by the sexual practices of those raising the children, but one could use the investigatory triggers.

    • JayMan / Oct 21 2013 5:08 PM

      @James A. Donald:

      The only way to reliably study the effects of gay parents (or for that matter, any “family constellation variable”) is with the equivalent of a randomized controlled trial – you need to study adopted children, and then you would have to ensure that there are no systematic differences in the way the children were adopted to the respective homes (in gay vs. straight parents).

      By your standard, there can never be scientific evidence that gay and lesbian child rearing practices are frequently outside the norm. How convenient.

      I wouldn’t say never. To paraphrase Gary Taubes, just because our only research options are shitty doesn’t make that shitty research any less shitty.

      With an effect as large as this, genetics cannot confound matters significantly. You are not explaining the data, but explaining the data away, and your explanation is weak.

      All human behavioral traits are heritable, as I’ve noted ad nauseum. I’ve explained the data and the uselessness of this research. Your personal incredulity is evidence of didly-squat.

      This, of course, is a collection of anecdotes, and suffers from the problem that only spectacularly horrid cases come to our attention, but it is certainly suggestive.

      And therein lies your problem.

      One solution would be a uniform policy of looking for and investigating signs of child abuse – unwashed children showing up at school, hungry children at school, bruised children showing up at school, children with sexually transmitted diseases, self harming behavior at school, and then determine to what extent these symptoms correlated with being raised by gays and lesbians. One could not use the results of the investigations, because you would doubtless argue that the investigators would be influenced by the sexual practices of those raising the children, but one could use the investigatory triggers.

      Indeed. One can measure the average properties of how gay and straight parents claim to treat their children, as well as other markers such as the on you and “redneck” mentioned to at least (limitely) assess the nature of gay parents. That would at least give us some idea of how gay parents fare as opposed to straight parents.

      It wouldn’t tell us about the children’s outcomes, but it might at least give us an idea of how “normal” gay parents are.

      Please think very carefully about your next reply. I’ve allowed this comment through because there were some ideas of merit. If I don’t see that continuing I will have to put you on moderation.

  2. Luke Lea / Oct 19 2013 11:45 PM

    Damn, you are good!

    • JayMan / Oct 20 2013 12:19 AM

      Thank you! 🙂

  3. feministx / Oct 20 2013 12:17 AM

    “while children with gay male “parents” were only 69% as likely (daughters 15%, sons 161%).”

    How in the world can that possibly happen? Even if you believed entirely in nurture, how can you explain a disparity like that? 15% as likely to graduate? That’s lower than the comparison of daughters from single mother households vs married households. Ok, father daughter relationship is influential, but what could gay male parents possibly be doing that is so awful for daughters that they become 15% as likely to graduate while sons are 161% more likely to graduate?

    Personally, I am really suspicious of this sample because of a bizarre finding like that. There must be something adoption related happening there. My hypothesis is that since these are studies of children who were born in the 90s, gay men had a really hard time adopting sons because people feared molestation etc. Maybe all they could get was adopted daughters? I would guess that a much higher proportion of gay men’s sons are biological whereas the daughters are more likely to be adopted. How else can you get to a disparity like that? Even in a blank slate world, that finding is insane.

  4. Jorge Videla / Oct 20 2013 1:07 AM

    “Even if there were differences in the exact treatment each child received, there are going to be systematic similarities with the way each set of parents treat all their children. If such an effect existed, it would turn up in the shared environment, since kids growing up together would be impacted by these across the board similarities. But the shared environment influence is in fact negligible.”

    wrong. the supposed null effect of shared environment is due to the effects of environment varying from one genome to another. what is best for child a may not be be best for child b, etc.

    [JayMan: I’ve removed your last sentence. No more of the gratuitous mudslinging, please]

    • JayMan / Oct 20 2013 12:48 PM

      @ Jorge Videla:

      wrong. the supposed null effect of shared environment is due to the effects of environment varying from one genome to another. what is best for child a may not be be best for child b, etc.

      Please reread the post. That idea is bankrupt.

      I’ve placed you on moderation, mainly because I’m tired of monitoring your comments. Please keep it civil, rationally sound, and tone down on the hatefulness, thanks.

  5. georgesdelatour / Oct 20 2013 7:34 AM

    In most cases, children follow the religion of their parents. That parental religion may affect which other children they’re allowed to socialise with, and even marry.

    I don’t know how much it changes a child to be brought up Catholic, Jewish, Muslim, Scientologist or Atheist. But I’d be amazed if the effect was zero.

    It’s difficult to study the effects of religious upbringing isolated from the issue of family ethnicity. Have any researchers tried?

    • JayMan / Oct 21 2013 4:29 PM

      @georgesdelatour:

      In most cases, children follow the religion of their parents.

      Religiosity is heritable. With respect to mixed groups, so is particular religion.

      That parental religion may affect which other children they’re allowed to socialise with, and even marry.

      But how much would all that matter if the mores weren’t enforced by the community?

      I don’t know how much it changes a child to be brought up Catholic, Jewish, Muslim, Scientologist or Atheist. But I’d be amazed if the effect was zero. It’s difficult to study the effects of religious upbringing isolated from the issue of family ethnicity. Have any researchers tried?

      While behavioral genetic samples tend to be lily White, many do contain significant religious mixes. The shared environment term comes back as zero.

      But yes I agree, we need larger, more “diverse” behavioral genetic samples.

    • georgesdelatour / Oct 22 2013 8:33 AM

      Thanks for replying. I realise I’m pulling the discussion way off topic. So I may as well continue 🙂

      Do adopted children tend to revert to the religion of their biological parents? I suppose investigating this would be incredibly suggestive if adoptees were found reverting to their birth parents’ religion without ever having been told what that religion was.

      Steve Jobs seems to have embraced the hippy eastern spirituality of his generation, rather than the Syrian or Swiss Christianity of his biological parents (his father’s religiosity seems never to have been especially devout – he now manages a casino). Don’t know if that tells us much…

      I’ve read about Polish anti-Semites who’ve suddenly discovered their grandparents were Jewish, and then decided to convert to Judaism. But that seems to show they’re simply extreme personality types with an identity crisis. The kind of person who can only be an alcoholic or teetotal, but who can’t do moderate, responsible drinking.

      The most extreme example I can think of is David Myatt, who went from British Neo-Nazi to Muslim extremist; not because of any family connection to Islam, but, again, because he clearly has an extreme type of personality. When he finally came to choose a religion, after quite a religious quest, he needed it to seem shocking and unacceptable to people. The occultism of Aleister Crowley used to have that shock value in the 70s and 80s. Now it’s a bit passé. So Islam it was. For a time, at least.

    • JayMan / Oct 22 2013 7:15 PM

      @georgesdelatour:

      No problem.

      The whole point of the three laws of behavioral genetics (see All Human Behavioral Traits are Heritable) is that all human traits show genetic influence, and the shared environment term is at best small and usually absent. That is, the effect of growing up within a particular family disappears upon adulthood. Similarities within families are entirely due to shared genes.

      Now to your specific point, there haven’t been many adoptions studies on religiosity, but there have been plenty of twin studies. The largest, especially those that look at adults, find that the shared environment (“family influence”) is absent to negligible, and genetic components large.

      See here, here, and here.

      Now it’s worth mentioning there is a restriction of range within most behavioral genetic studies. Those that look at religiosity tend to have been done on White Americans (the three largest from Minnesota, Colorado, and Virginia). The prevents us from looking too closely at the specific religion (and then, that might be limited by what’s locally available), but as far as religious behavior, the pattern follows that as noted above.

      But overall, the effects of religion will be primarily a heredity one.

    • georgesdelatour / Oct 24 2013 7:14 AM

      I can understand that, say, musical ability might be highly heritable. But the idea of a genetic predisposition to be a highly specific type of musician – say a virtuoso contrabass bassoonist or an electric sitarist – that seems to be expecting too much of the genes. Surely the outlet for someone’s musical ability changes over time, as the culture changes the available musical options.

      In recent years we’ve seen an explosion of virtuoso Chinese musicians playing western Classical instruments. But those instruments and that repertoire are relatively recent arrivals in China; the result of cultural transmission.

      Similarly I expect religiosity – broadly defined – might be heritable. But the culture determines the religious options available at any moment. Being a Zeus worshipper just isn’t a realistic option in 2013, for instance. I suspect that’s because culture has removed the Zeus option, rather than that natural selection has removed the Zeus gene.

    • JayMan / Oct 30 2013 2:43 PM

      @georgesdelatour:

      I haven’t forgotten about you! I’m behind on most of my comments.

      I can understand that, say, musical ability might be highly heritable. But the idea of a genetic predisposition to be a highly specific type of musician – say a virtuoso contrabass bassoonist or an electric sitarist – that seems to be expecting too much of the genes. Surely the outlet for someone’s musical ability changes over time, as the culture changes the available musical options.

      That depends, yes? You can’t be predisposed to something that doesn’t exist in your environment (for example, Ancient Greeks couldn’t have had any basketball talent). But, your genes do impact your inclinations given the options available. In today’s environment, with a wide range of musical instrument, one could be more inclined to be a master bassoonist over a pianist. Obviously this isn’t an issue where these items don’t exist.

      In recent years we’ve seen an explosion of virtuoso Chinese musicians playing western Classical instruments. But those instruments and that repertoire are relatively recent arrivals in China; the result of cultural transmission.

      The same set of genotypes can result in different phenotypes in a new environment. Take these Chinese, put them in a world of Western instruments, what you see is what results.

      Similarly I expect religiosity – broadly defined – might be heritable. But the culture determines the religious options available at any moment. Being a Zeus worshipper just isn’t a realistic option in 2013, for instance. I suspect that’s because culture has removed the Zeus option, rather than that natural selection has removed the Zeus gene.

      Precisely, though don’t be surprised that among the religions available, there is some heritable impact.

      Genes can’t make you choose from choices you don’t have. But they certain can influence what you pick from what you do have….

  6. Staffan / Oct 20 2013 8:27 AM

    Great post.

    “The failure to recognize the broad null effect of nurture (“The Nurture Assumption”) is pervasive even in the HBD community, the people who should of all know better.”

    There is probably a political bias here since HBD is largely conservative. I noted a similar effect when Philip Cohen discredits this study as a leftist he can’t use the fact that minorities might not graduate so often even with well-meaning gay/liberal parents.

    Still, I’m not happy about gay parents. I’d like a study that says that the children report the same level of well-being as other kids before I’m ok with it.

    And it’s interesting and weird that out of 279 randomly selected same-sex couples, not a single one is interracial, not even White/Asian. According to Wikipedia the visible minority in Canada is 20 percent of the population.

    • JayMan / Oct 20 2013 12:22 PM

      @Staffan:
      Thank you!

      “The failure to recognize the broad null effect of nurture (“The Nurture Assumption”) is pervasive even in the HBD community, the people who should of all know better.”

      There is probably a political bias here since HBD is largely conservative. I noted a similar effect when Philip Cohen discredits this study as a leftist he can’t use the fact that minorities might not graduate so often even with well-meaning gay/liberal parents.

      Indeed.

      Still, I’m not happy about gay parents. I’d like a study that says that the children report the same level of well-being as other kids before I’m ok with it.

      I think you might be missing the point of this post. A proper study of the sort would be impossible to construct because the children of gay parents aren’t genetically equivalent to the children of straight parents.

      Even trying to use adopted children would have problems. See here. Skip to the second segment. The children that get adopted by gay families are likely to be of lower “quality”, in a varieties of ways, than those adopted by straight parents.

      And even beyond that, this misses the key point: parenting doesn’t have an effect on how children turn out. So then, why would it matter if those parents were gay? Either parenting doesn’t have an effect, or gay vs. straight parents matter. Those notions are mutually exclusive.

    • szopeno / Oct 25 2013 1:06 PM

      Jayman, exactly! I came to this conclusion just few months ago, when writing about Moynihan report. For some time I was aware about lack of effect of parenting on children, and at the same time I was giving willing ear to those accusing those evil liberals and feminists destroying afroamerican family, which was cause to all the problems plaguing this commmunity.

      THen, suddenly something went click! and I realised the contradiction 🙂

    • JayMan / Oct 26 2013 12:34 PM

      @szopeno:

      Indeed. That was one of those “wait a minute” moments. Worry about the “collapse of the family” is a right-wing canard. It has nothing to do with nothing, past dysgenics, which itself is really more of a factor of clean, safe, modern society.

  7. Staffan / Oct 20 2013 12:39 PM

    Well, the obvious way to conduct that study would be to adjust for such differences.

    My objection is about state rather than trait. As Judith Rich Harris pointed out, even children who grow up in concentration camps (anectdotally) turn out perfectly normal. But they can’t possible have enjoyed it. I don’t think having your personality and intellectual abilities intact is enough to justify allowing gay parents. I want the children to have good childhoods as well.

    • JayMan / Oct 20 2013 12:43 PM

      @Staffan:

      Well, the obvious way to conduct that study would be to adjust for such differences.

      How?

      My objection is about state rather than trait. As Judith Rich Harris pointed out, even children who grow up in concentration camps (anectdotally) turn out perfectly normal. But they can’t possible have enjoyed it. I don’t think having your personality and intellectual abilities intact is enough to justify allowing gay parents. I want the children to have good childhoods as well.

      Well, we can’t guarantee that the children of straight parents will have happy childhoods. We have no reason to suspect a negative long-term impact, based on the evidence we have. It would seem that such scrutiny is just looking for something to be wrong.

  8. Staffan / Oct 20 2013 1:01 PM

    If children raised by gays have an IQ of 95, we look at the other kids at that level. And so forth.

    There are no guarantees for anything but kids tend to be conformist and will bully someone who has odd looking clothes. Would they ignore gay parents?

    • JayMan / Oct 20 2013 1:05 PM

      @Staffan:

      If children raised by gays have an IQ of 95, we look at the other kids at that level. And so forth.

      They could differ in other ways, ways that we’re not considering. There’s only so much you can learn from correlational studies, especially parenting ones. You can’t really perform a study like this.

      There are no guarantees for anything but kids tend to be conformist and will bully someone who has odd looking clothes. Would they ignore gay parents?

      Fair point, but then even that could be a function of the traits of these kids themselves.

  9. Luke Lea / Oct 21 2013 9:43 AM

    OT but here is a fascinating piece of political analysis if you haven’t seen it already: http://akarlin.com/2009/09/08/struggle-europe-mankind/

  10. Rafael / Oct 22 2013 11:09 AM

    Ok, nice discussion and everything, but… The thing that is the most striking has been touched very little upon. What with the dramatic differences with the sexes?
    And this is not only for gay parents but also for lesbian parents (the differenceis smaller but in the same direction). I don’t see how to marry this with the genes/nature effect.
    Perhaps there are different treshholds for boys and for girls what constitutes normal parenting? Perhaps boys can tolerate much more then girls?

    • JayMan / Oct 22 2013 11:17 AM

      @Rafael:

      Ok, nice discussion and everything, but… The thing that is the most striking has been touched very little upon. What with the dramatic differences with the sexes?

      As per szopeno’s comment, sample sizes were small. As well, the nature of the children in these families were likely quite heterogenous in terms of origins and racial composition. Between this and sampling error, their findings are essentially completely worthless.

      And this is not only for gay parents but also for lesbian parents (the differenceis smaller but in the same direction). I don’t see how to marry this with the genes/nature effect.

      Simple. See above.

  11. panjoomby / Oct 23 2013 11:00 AM

    the following is probably of interest only to Jayman – & maybe not even him:)

    “The proportion of total variance accounted for in outcomes such as adjustment, personality and cognition was 0.01 for family constellation, 0.02 for differential parental behaviour, 0.02 for differential sibling interaction and 0.05 for differential peer or teacher interaction.”

    i’m guessing these are r-squareds, & with the huge sample they’re probably statistically significant at alpha = .05 (or p < .05 whatever), BUT if those r-squareds come from statistically NONsignificant r's, then these r-squareds should merely be considered 0. & even if they are statistically significant, another way to interpret them is as we go up 1 standard deviation on the independent variable, we go up .01 standard deviation on the family constellation variable, etc. In any event, they're so tiny as to be inconsequential, obviously:)

    • JayMan / Oct 23 2013 11:05 AM

      @panjoomby:

      Pretty much. And then these are purely correlational – unlike correlation with genes or IQ, you can’t infer causation from them.

  12. imnobody00 / Oct 24 2013 11:03 PM

    In science, the load of burden is with the person making the claim. This study suggests that gay parenting does not give as good results as straight parenting. Yes, the proof is not conclusive and more research is needed but, with the data we have today, the odds are against gay parenting.

    I don’t think you can dismiss this study on the grounds that parenting does not matter. This is not the first time several scientific studies are apparently contradictory. There are three possibilities: 1. Studies saying parenting does not matter are wrong 2. Studies saying gay parenting is bad are wrong 3. The contradiction is only apparent. Both studies are right and some of our assumptions are wrong (the most interesting progresses in science come from this).

    Your attempt to dismiss this study on the grounds of being contradictory with others is option 2 but we have no evidence to support that. This is why you are making a claim without evidence. And no, the contradiction is not evidence. People said that was impossible for the Earth to rotate because birds would not stay over the same place. This was a contradiction with the experience that people had about movement but it was only an apparent contradiction.

    • JayMan / Oct 24 2013 11:10 PM

      @imnobody00:

      In science, the load of burden is with the person making the claim.

      Indeed it does.

      This study suggests that gay parenting does not give as good results as straight parenting. Yes, the proof is not conclusive and more research

      In isolation, it might suggest that, but with other evidence, it suggests nothing of the sort.

      I don’t think you can dismiss this study on the grounds that parenting does not matter.

      I most certainly can, at least as far as it the claim parenting has a significant impact on adult behavioral traits, as per the totality of the evidence.

      I don’t think you can dismiss this study on the grounds that parenting does not matter. This is not the first time several scientific studies are apparently contradictory. There are three possibilities: 1. Studies saying parenting does not matter are wrong 2. Studies saying gay parenting is bad are wrong

      There is no inherent contradiction, because of the sampling and other methodological weaknesses in the study. Hence, there is no need to analyze this “conflict” further.

      Your attempt to dismiss this study on the grounds of being contradictory with others is option 2 but we have no evidence to support that. This is why you are making a claim without evidence.

      No, I am dismissing the study because it’s inherently incapable of answering question about gay parenting, which we have reason to believe has no impact thanks to other evidence. Let’s be clear on that.

    • imnobody00 / Oct 24 2013 11:42 PM

      “Hence, there is no need to analyze this “conflict” further.”

      Well, with this attitude, it is useless to discuss. You are emotionally invested in your opinion and no study will be enough for you to consider if it goes against your opinion (I don’t say to accept, only consider). You will always find a flaw. As some book I read said, there are not completely proven facts (even the existence of the external world cannot be proven). There are only conjectures and we demand a level of evidence to accept them. But, as the book whose name I don’t remember says, we demand different levels to different conjectures in order to accept them as a true. For the conjectures that are against our worldview, we demand a much higher level of evidence than for the ones that support our worldview. This is what happens here.

      I am not saying that this study is conclusive. But the fact that you claim that it proves the opposite of what really suggest speaks volume. The fact that you refuse to analyze speaks volumes too. This is not a scientific attitude but an ideological attitude, not unlike that of a guy who does not want to consider the evidence of the Earth being older than 6000 years old. S

      So it’s useless to discuss this with you. You can have the final word. And yo can ban me, if you want. After all, this is your blog and Galileo was also banned. The truth, whatever it is, will eventually prevail.

    • JayMan / Oct 25 2013 12:06 AM

      @imnobody00:
      You’re welcome to discuss here, but I have the task of keeping the discussion rationally on track. As you can see from the previous comments, your point is hardly original, and while you do point out some key points, from a point of due skepticism, it is nonetheless a point that is ignorant of the facts, and thus not horrendously productive, if you understand what I mean.

      Well, with this attitude, it is useless to discuss. You are emotionally invested in your opinion and no study will be enough for you to consider if it goes against your opinion

      No, I’m only interested in seeking the truth. My mind is swayed by evidence, but you were not presenting much here. Please don’t confuse my disagreement with you on this point as “emotional investment” on mine.

      As some book I read said, there are not completely proven facts (even the existence of the external world cannot be proven).

      You’re talking about absolute truth. Facts, generally, aren’t absolute truths, unless it’s in the realm of mathematics (and by extension, logic), since absolute truth is impossible to attain outside that realm. However, facts are claims which, as per evidence we have, are highly likely to be true. However, that whole problem isn’t much of an issue here.

      But the fact that you claim that it proves the opposite of what really suggest speaks volume.

      I’ve made no statement about what the study proves. In fact, the whole point of this post was that it doesn’t prove much. Please don’t confuse your own emotional investment (in this case, revulsion with gay parenting) as facts themselves.

  13. imnobody00 / Oct 24 2013 11:19 PM

    The previous comment was from the point of view of science, but gay parenting is not only about science but also about public policy. Public policy has different rules from science. In a public policy decision related to health, the burden of the proof is on the people who claim the thing is healthy. It should be proved that the thing is healthy before it is allowed. Imagine a drug with a study that suggest that it is bad for health. Should this drug be allowed by the FDA? Of course not. More studies have to be done but until the drug is not proved healthy, it should be forbidden.

    We know how straight parenting works because we have experienced that for millennia. We need to know that gay parenting is not bad before it is authorized. We are dealing with the life of kids, not about lab rats. I know that there are people (I am not talking about you) that love more their ideology than the life of kids and are able to rationalize everything that goes against their ideology, even if it means harming other humans. They are not different from the religious fanatic that harms other people because of his religion.

    • JayMan / Oct 24 2013 11:23 PM

      @imnobody00:

      The previous comment was from the point of view of science, but gay parenting is not only about science but also about public policy. Public policy has different rules from science.

      When it comes for our quest for truth, that doesn’t mean we can through science out the window for the sake of “public policy”. If anything, public policy should be far more informed by science.

      In a public policy decision related to health, the burden of the proof is on the people who claim the thing is healthy.

      This blog proceeds from a scientific viewpoint. If you want to debate from other viewpoints, please go elsewhere.

      We know how straight parenting works because we have experienced that for millennia. We need to know that gay parenting is not bad before it is authorized. We are dealing with the life of kids, not about lab rats.

      In other words, you’ve got nothing, so you’re taking a different track. See special pleading.

    • imnobody00 / Oct 24 2013 11:57 PM

      I am not going to a different track. I am explaining other aspect of the same issue. I explained the original aspect in the previous comment. Fair enough, this is not a blog about public policy so I may have been talking about things unrelated. But I thought it was appropiate, maybe mistakenly. You can delete my post if you want.

      Anyway, this is my last post. I didn’t know you and I thought it was possible to have a polite and rational discussion with somebody who is tolerant of other points of view. My mistake. Please ban me. It will be an honor to be banned by people like you.

  14. JayMan / Oct 24 2013 11:30 PM

    Jorge Videla, for that last comment, you’ve gone from on moderation to banned. Goodbye, and good luck!

    • Anonymous / Oct 25 2013 12:05 AM

      what makes you think you can ban anyone?

    • JayMan / Oct 25 2013 12:07 AM

      Because it’s my blog.

  15. Rome's Creature / Oct 25 2013 5:41 AM

    I’ve suspected for a while that particular long-term effects from being raised in a gay household are marginal, barring extreme treatment of any kind. This is the only logical conclusion if all human behavioral traits are heritable.

    Rightists in HBD circles may jerk knees here, but I’d say it’s far more of a nightmare for the blank-slatist Left than it is for them. Picture a couple of SWPL parents recoiling in horror as their adopted Ugandan child embraces “bigotry” despite their best efforts.

    What rankles is outbred liberals directing their messianic impulses at us homophobic folks. I certainly don’t appreciate the intention anymore than I do the aesthetics. Some performance art piece featuring a young man losing his anal virginity doesn’t strike me as beautiful cultural expression, and those who feel otherwise won’t be content with agreeing to disagree so long as they run the national show.

    A Cavalier-led regime would be authoritarian on balance, but they might not lord their ideologies over everyone in the manner of today’s rulers: Cough up taxes and enjoy wide leeway in your Yankee locality. Withholding of revenue or promotion of your moral norms will be met with . . . displeasure.

    • JayMan / Oct 25 2013 11:26 AM

      @Rome’s Creature:

      I’ve suspected for a while that particular long-term effects from being raised in a gay household are marginal, barring extreme treatment of any kind. This is the only logical conclusion if all human behavioral traits are heritable.

      Rightists in HBD circles may jerk knees here, but I’d say it’s far more of a nightmare for the blank-slatist Left than it is for them. Picture a couple of SWPL parents recoiling in horror as their adopted Ugandan child embraces “bigotry” despite their best efforts.

      Indeed. Very well said!

      A Cavalier-led regime would be authoritarian on balance, but they might not lord their ideologies over everyone in the manner of today’s rulers: Cough up taxes and enjoy wide leeway in your Yankee locality. Withholding of revenue or promotion of your moral norms will be met with . . . displeasure.

      A key problem with Cavalier leadership is their penchant for exploitation. “It’s good to be the king” is the phrase that comes to mind. Colin Woodard argues that in many ways, the Cavaliers already run the country, as he argues that many of the policies in place – including those despised by HBD rightists – are those of the Deep Southern slave lords:
      From Regional Differences Have Doomed the Tea Party | Ten Miles Square | The Washington Monthly:

      [The Deep South] is a region founded by West Indies slave plantation owners, men who cherished and fought for a form of classical Republicanism modeled on Ancient Greece and Rome, where a privileged minority enjoyed liberty and democracy, and slavery was the natural lot of the many. The agenda of the Deep Southern oligarchy has been consistent for more than three centuries: to control and maintain a one party state with a colonial-style economy staffed by a compliant, low-wage workforce with as few labor, workplace safety, health care, and environmental regulations as possible. Its slave and racial caste systems have been smashed by outside intervention, but its representatives in Washington have continued to fight to reduce federal power, taxes on the rich, and rolling back labor and environmental protection, and social service programs. Not coincidently, these are also the central goals of the tea party caucus.

      From On the Rise of the (Deep) Southern Oligarchy | Ten Miles Square | The Washington Monthly:

      The radicalization of the Republican Party in recent years has a lot to do with it having been taken over by Deep Southerners like Trent Lott and Newt Gingrich, Dick Armey and George W. Bush, Haley Barbour and Jim DeMint. The central policy goals of Tea Party Republicanism mirror those of the Deep Southern elite: rollback federal power, environmental, labor, and consumer protection laws, and taxes on capital and the wealthy. It’s a program one never would have seen in the days when the GOP was run by Yankee – read “Greater New Englander” – figures like Teddy Roosevelt or George Bush the senior.

      (Though, of course, to be fair, Dubya is of course also a Yankee.)

      From A Geography Lesson for the Tea Party by Colin Woodard | The Washington Monthly:

      In office [the Deep Southern oligarchy] … focused on cutting taxes for the rich, funneling massive subsidies to agribusiness and oil companies, rolling back labor and environmental programs, and creating “guest worker” programs and “right to work” laws to ensure a cheap, compliant labor supply.

      This sentiment, especially with respect to Deep Southern oligarch support for mass immigration, has been echoed by Michael Lind:

      In state after state controlled by Republican governors and legislators, a fictitious epidemic of voter fraud is being used as an excuse for onerous voter registration requirements which have the effect, and the manifest purpose, of disenfranchising disproportionately poor blacks and Latinos. The upscale leaders of the Newest Right also tend to have be more supportive of mass immigration than their downscale populist supporters—on the condition, however, that “guest workers” and amnestied illegal immigrants not be allowed to vote or become citizens any time soon. In the twenty-first century, as in the twentieth and nineteenth, the Southern ideal is a society in which local white elites lord it over a largely-nonwhite population of poor workers who can’t vote.

      There is a reason I used The Imperial March to represent the Cavaliers.
      J.R. Ewing is a perfect characterization and symbol of the Deep Southern oligarch.

  16. vijay / Oct 25 2013 2:10 PM

    This paper has some doubtful mathematics; economists doing sociology are often indulgent in questionable math. instead of writing out my objects, I point to sociologist commentary at http://familyinequality.wordpress.com/2013/10/11/the-douglas-allen-study-of-canadian-children-of-gaylesbian-parents-is-worthless/

  17. Rome's Creature / Oct 25 2013 10:39 PM

    @JayMan:

    Absolutely. The flip side is that while Yankees are not exploitative, they are very conformist and intellectually overbearing.

    I don’t take issue with caste systems per se. My grievance is when they function at the racial expense of commoners, which was less the case in the antebellum South than in our modern one. Many American HBD-rightists have professed resentment toward the old plantation lords for importing sub-Saharan Africans in the first place.

    Perhaps the northern alliance wouldn’t have objected as strongly if “free” Irish labor were used to pick those cash crops on slave wages, though I’m not sure Ireland could’ve supplied the manpower required at the time. What’s more, keeping an Irish peasantry under heel sounds relatively difficult (the same might’ve applied to aboriginal peoples had they not been obliterated by smallpox, measles and all the rest of it).

    The situation now involves Midlanders and Yankees leading as the self-appointed moral authority over Cavaliers and Appalachians, who provide the military muscle. Rising non-white enlistment and trends in conservative fertility can only destabilize this arrangement. I think it would be at least slightly easier for inbred Euro-Americans to work with their outbred countrymen against demographic problems if the former respected the latter, and that’s tough given how meek and effeminate white liberals have become since World War II.

  18. Amber / Oct 26 2013 1:27 AM

    Did they not control for adoption/genetic donation? That would seem like a huge oversight.

    • JayMan / Oct 26 2013 1:29 AM

      @Amber:

      One would think so, yes? But the author did nothing if the sort.

  19. Amber / Oct 26 2013 1:49 AM

    Eh, second thought. The thing about parenting not mattering is that it doesn’t matter in the *long term*. If you and I both have one of a pair of 4 yr old identical twins, and I sit down today and start drilling mine on phonics, and you wait until yours starts kindergarten, mine will be “ahead” when they both start kindergarten. By the time they graduate, the effects of this pre-k training will be gone.

    Normal parenting may not have any long-term effects, but whether a kid graduates from highschool could have to do with short-term household conditions while they were in highschool. (EG, I dropped out of highschool because of some severe illnesses in my [hetero] family. [And graduated later.]) A later measure of intelligence may show no effect. (EG, I scored a 1570 on my SATs, back when 1600 was the max.)

    Personally, though, I’d hold out for something along the lines of “toddlers adopted from Romanian orphanages have abysmal graduation rates” as the explanation. Occam’s razor and all that.

  20. Kubik / Oct 30 2013 9:14 AM

    IQ, personality, etc. may show little shared environmental influence, but that does not necessarily generalize to educational outcomes in America. See this paper, and this one. Also, the lack of shared environmentality does not rule out substantial gene-environment interactions, as shown by Bates et al. recently.

    Based on the available evidence, I’m not concinved that gay parenting causes worse educational outcomes than straight parenting, ceteris paribus, but you are overselling the “nurture fallacy” thesis.

    • JayMan / Oct 30 2013 1:37 PM

      @Kubik:

      You have made we work this morning! 🙂 But that’s good, it’s always good to bring up new information and data that may challenge what I claim here.

      That said, let’s see if you’ve done that:

      The Nielsen & Roos paper is interesting. Indeed, even they admit finding a large shared environment effect is anomalous (though not unheard of, see here). They also suggest an explanation for why this is so:

      Highest degree earned or years of education completed constitute rather undifferentiated measures of educational attainment that do not distinguish degrees according to the selectivity, prestige or “quality” (however defined) of the institution where it is earned, so that a degrees from a nonselective college and from an elite university (and the years spent earning it) are rated the same with respect to attainment. One could speculate that if one had a measure of attainment incorporating the “quality” of the degree earned, and to the extent that entering and graduating from a higher quality institution is more cognitively demanding, such a measure would behave from a quantitative genetic viewpoint more like a cognitive measure. The very strong effect of standardized test scores (such as the SAT or ACT) on admission to more selective institutions is consistent with that scenario (Briggs 2001; Buchmann, Condron and Roscigno 2010). One would predict that the quantitative genetic structure of such a quality-weighted measure of educational attainment would tend to resemble that of IQ, with a stronger effect of genes (heritability) and a weaker impact of the shared environment.

      The other issue that they discuss:

      The system of tertiary education in the U.S. is highly diverse, consisting of a whole range of institutions, some public and some private, that differ widely in the cost of education for students and their families. A complex assortment of scholarships and financial aid programs further complicates the picture. Our finding of a large shared environment effect suggests that, overall, the pursuit of a university education in the contemporary U.S. is more likely to be constrained by availability of resources on the part of students and their families. The pattern of a persistent effect of the shared environment on educational attainment may well be related to “mechanical” effects of family resources on the chances of entering, and graduating from, college. To the extent that our results can be compared to those of Behrman and Taubman (1989), which are based on a somewhat different methodology, they suggest that there has been a considerable worsening in inequality of educational opportunity in the last few decades … We do not have a theory at present why there would be such a trend of increasing inequality of educational opportunity in the U.S.

      As they note, other studies on the matter do not find this large shared environment effect on educational attainment.

      Even further, even if there is a shared environment effect on degree attained, that doesn’t seem to translate to income. After all, what good is a degree, in the long run, if it is not backed by the cognitive and temperamental traits to support it? Shared environment effect is not found on average income (Cesarini paper here).

      As for the Hoxby and Avery paper, they compared high-acheiving students from low-income vs. high-income backgrounds, but they defined “high-acheiveing” essentially solely by SAT/ACT score (i.e., IQ). High-IQ individuals that differ in wealth differ in other ways, not only by race, as noted in the paper, but by political orientation (White low-income students more likely to conservative, for example), among other traits. Hence, it’s not exactly proper to use “income” for the effect of upbringing, because even that is a partially genetic effect.

      And as for the Bates paper, that was heavily discussed in the commentary over at Steve Hsu’s. Two key problems with the paper – my two big concern with it – are:

      • It includes a diverse range of ages in the study. Generational effects may be confounding their findings.
      • It doesn’t make clear if the effect they found was on g. Indeed, in the discussion, Bates seems to indicate that it isn’t.

      The gene-environment correlation theory was deeply scrutinized by Meng Hu. It doesn’t have a lot going for it. See here:

      The Genetics of Intelligence « Meng Hu’s Blog

      What you’ve found is interesting. That said, I’m remaining with the position that the “nurture fallacy” is in fact that.

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