Sometimes rare experimental outcomes tell you a lot, as when a few of the alpha particles impinging on a gold foil were scattered straight back [Geiger-Marsden experiment] , implying that most of the mass and positive charge of an atom is concentrated in a tiny nucleus.

Let’s think about the Jim Twins. Chevys, Miller Lite,  migraines, chain-smoking, finger-nail chewing, baseball hating,  vacationing on the same three-block beach near St, Petersburg, both leaving love notes around the house, both building a circular white bench around a tree in the front yard. Tests of intelligence, personality, heart rate, and brain waves were about as  similar as the same person taking the test twice.

Let’s face it: the Jim Twins were the same guy twice. At least in this case,  Nature utterly pwned Nurture.

Sure,  neither could have driven a Chevy in 1500, or had a Miller Lite – so the environment influenced them all right, but it influenced them in exactly the same way.  Your preferences can be your constraints.  They were exposed to similar environments ( raised in similar small towns in Ohio) – but there are always differences. Different adoptive parents,  different schools, different teachers,  different friends – but none of those differences seem to have had any lasting consequences.

If many small influences kept nudging them, differences should have grown with time, like a random walk.  Didn’t happen.  Along the same line, heritability of intelligence increases with age: people converge onto the predicted phenotype.  Again, little differences don’t accumulate.

In order for that to be the case –  the development process has to be canalized. Most environmental differences must end up having no effect – they don’t generate differences between twins. Let me try an analogy. Think of a river basin: a drop of rain that falls into the Rio Grande basin is going to end up in the Caribbean, whether it lands in Taos or Albuquerque or El Paso. It matters which basin a drop lands ( Rio Grande vs Colorado), but it doesn’t matter where in that basin lands.

What can knock you into a different basin?  Make you a different person? Well, trauma can: closed head injury, firing a steel rod through your head (Phineas Gage), serious illness ( Helen Keller), shortage of a vital nutrient ( iodine and cretins). However those aren’t the environmental influences people want to exist: they want going to school X instead of school Y to make a difference (in your capabilities or personality: X and Y can certainly put different ideas in your head, for instance if X=More Science and Y = Commie Martyrs). Or, winning the lottery ought to make people different (in personality and capabilities) – but it doesn’t. Not in typical modern circumstances, anyhow: in medieval times t might well have kept you from starving to death.

The environment influences people want to exist, mostly don’t.

In order to push people into a different basin of attraction, make them a different person, you apparently need to to thump them pretty hard. In the cases we understand,  that means damage.

Usually when a guy is homosexual, his identical twin is not. Family environment doesn’t look to be the cause:  something thumped the homosexual twin.


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207 Responses to Landscapes

  1. Hesse Kassel says:

    On average, the gap between two random walks does not widen more and more as time passes. It widens less and less.

    • catte says:

      so in other words, the gap widens more and more.

    • Erik says:

      The gap between two random walks can either widen, narrow, or stay the same. “Widen more” or “widen less” is a nonsense statement in this context; there’s no second reference gap for it to widen less than.

      Here is a summary argument that it widens:

      At some time T there is a gap between the random walks 1 and 2. (If no such time T exists, the walks are not random.)
      Draw a circle surrounding the current point of random walk 2, with radius equal to the distance between them.
      Draw a second circle surrounding the current point of random walk 1, with radius equal to the maximum distance it can move in N steps.

      Less than half of the second circle lies within the first circle. So the first random walk is more likely to widen than narrow the gap during its next N steps. Ergo, the gap widens on average.

      (Of course this assumes an unbounded world to walk in, and other mathematical conveniences.)

      • Jim says:

        There is a difference between random walk in less than three dimensions and random walk in 3 or more dimensions. A particle undergoing simple random walk in less than 3 dimensions returns to the origin infinitely often with probability one. But in 3 or more dimensions the particle will permanently leave any bounded area with probability one.

        • catte says:

          this is trivially true but is also useless. the most natural question to ask is what is the expectation of the absolute value of the difference between two random walks. for one-dimensional standard wiener processes, the expected absolute difference grows proportional to sqrt(t).

          • Jim says:

            Is it actually trivial? It was proven by Polya in 1921.

            • Space Ghost says:

              All math theorems are either trivial (already proven) or hard (not proven yet). And I guess some exist in a weird intermediate state where we don’t know if we can prove them or not.

              • Jim says:

                I think Polya used Laplace transforms in his proof. Subsequently the result was proven by purely combinatorial arguments. In general two particles in random walk in |R^2 will encounter each other infinitely often. But in |R^3 the distance between them will tend to infinity with time.

              • Jim says:

                Thus drunks should not be allowed to drive cars but it is OK for them to operate rocket ships in space.

            • catte says:

              I was referring to the 1D case, which has been known for a long time (gambler’s ruin).

  2. NobodyExpectsThe... says:

    I know the identical twins evidence goes against the underlying principle of the hypotesis. But I have been wanting to ask for a while;

    Has anyone ever looked at what are the rates of homosexuality on people, whose mothers were, for whatever reason, on antibiotics during pregnancy?

    • Frau Katze says:

      The book, “An Epidemic of Absence” is mostly about how our parasite-free environment has apparently screwed up some people’s immune systems. For no reason that seems to help overall survival, these unfortunates get autoimmune diseases or wild overreactions to harmless tree pollen and peanuts.

      But the books discusses other things. Antibiotics should be avoided if possible, they clean out your gut. Gut bacteria and parasites seem to be important (it can be studied in animals like mice and monkeys.). But the author recommends you do what your doctor says. He’s not a crank.

      The problem with mammals is that mother’s immune system must not attack the child she is carrying, but it still must protect her from the usual suspects. There is some evidence that sometimes the mother’s immune system may affect the baby.

      Antibiotics in pregnancy sound bad. Even if you’re not pregnant they could still cause problems. I haven’t finished the book and the emphasis is on autoimmune and allergies, but it is mentioned. No mention of homosexuality so far.

      • albatross says:

        Unnecessary antibiotics are probably a bad idea most of the time. If Mom has a serious infection, give her antibiotics that seem to be safe for her and the baby. But don’t hand her antibiotics every time she’s had a sinus infection for three days.

  3. Homosexuality was standard in Athens and Sparta in the classical period, and those guys weren’t all thumped. I remember reading that Athenians thought that Sophocles was odd because he wasn’t attracted to boys. A society that penalizes homosexuality will see something close to the minimum, the small percentage of men who are predisposed to it (thumped). A society that promotes it wil see a lot of it, including many of the unthumped. The fate of the Spartans is suggestive: their force of 10,000 soldiers declined to 1000. Aristotle noted the population decline.

    • bbloggz says:

      Adonis Georgiades has argued that broad social acceptance of homosexuality in Ancient Greece is a historical myth. I’m not qualified enough to render confident judgment on the merits of his argument, but considering the track record of how politically motivated biases have effected other academic fields, I wouldn’t be surprised if he was right.


      • Young says:

        I think outright homosexuality between adults was not favored in ancient Greece but pederasty was tolerated. There was one interesting combat unit composed entirely of homosexuals who generally did well in war but, if memory serves, Alexander the Great [who had his own Persian Boy and Haphaestion] killed all of them.

      • harpersnotes says:

        In societies of great inequality, such as when the majority of people are slaves as in ancient Athens and Sparta, forcible sexual coercion is common and often considered a basic right of the slave owners. This leads moderns to imagine homosexuality as tolerated in those places the way it’s tolerated in our individualistic societies of today. But in effect for most they are like the giant prisons of our time. And as in ancient Greece the households of citizens were sexually separated with the boys and girls interacting very little during their formative years. (Think boarding schools. I like to think of this as an availability heuristic for sexual attraction and preferences misfiring in non-hunter-gatherer environments.) Add to that the prevalence of rape in the Iliad and throughout Greek mythology, making the separation even more pronounced as a basic protection for free women. Were the rates of homosexuality higher than in modern prisons and boarding schools? Probably, but it’s hard to tell how much without the kinds of data we have for modern populations. In medieval Japan homosexuality seems to have been tolerated in much the similar fashion, embedded in a culture where peasants lives were considered almost insignificant and samurai or ronin could usually kill them without consequences. Much of the same general attitudes there and then seem similar as in ancient Greece, requiring a transition to masculine adulthood from passive boyhood and so on.

        To a lesser degree a similar logic might be explored in relation to the sex ratio during the Gold Rush and places like the San Francisco of today. Also more recently perhaps, the current increase in income and wealth inequality and the decline of marriage and fertility rates of today. But of course, there are many, many other factors as well.

        Greek Homosexuality (book)
        (See Demosthenes’ lawsuit.)

        The Myth of the Ancient Greek Gay Utopia.
        (Essay. Mentions slavery, but understates it’s importance.)

        (I don’t consider myself at all an expert on these matters, only an amateur with a life long interest in the history of Ancient Athens who has picked up some incidental information along the way. Feel free to disagree or enlighten me.)

      • Anonymous says:

        Adonis Georgiadis is currently vice president of the right-wing major opposition party in Greece and has been associated with various far-right parties and personalities in the past, so his essay is politically motivated, however he is right; one can reach his conclusions just by using common sense.

    • The Spartans looked down on such acts, contrary to what “ykw” would have you believe.

      A gay writing a homoerotic Spartan novel found this out himself doing research for his story:

    • mtkennedy21 says:

      The other factor was that classical Athens had women in harem-like social settings. Like prisons, when women are not available, homosexuality is more common. There was also a military system that used ephebes, young men mentored by older warriors.

  4. Dan Bagrov says:

    Say you have the money, how do you solve the mystery? How do you design a study to find the pathogen?

    • ghazisiz says:

      Plenty of readers here who submit NIH grant proposals. For someone this has to be a reasonable next step in their research trajectory. At least I hope so — I’m full of curiosity and would like to know the answer before I die.

  5. Bukephalos says:

    I always found the bit about their boy and dog having the same exact names…very fishy. I’m ready to accept heredity influences tastes and choices much more than commonly thought/admitted but with this level of specificity?

    • Rodep says:

      The lists of commonalities are misleading. When you scour the ENTIRETY of two people’s lives for commonalities, you can generate a very impressive sounding list of commonalities just by cherrypicking the hits.

      “They both hate baseball” is meant to sound representative, but if it was a typical case, the list could use a more-impressive outlier in it’s stead. We know they don’t share the same favourite movie, or it would have made the cut.

      • gcochran9 says:

        I left out some. As kids, they both named their dog Toy. They both had vasectomies. There were more such similarities. It’s not so much a case of cherry-picking as some refusing to believe stuff they don’t like.

        • Rodep says:

          They had different jobs! One divorced his Linda! Both of these are much more relevant to determining whether siblings are “the same person twice” than taste in names.

          My point is, these comparison lists are a rhetorical trick which operates on the same principle as numerology. People are easily wowed by “unlikely” connections because they don’t have an intuitive sense for how large the pool of possible comparisons is.

          When comparing fiction, people like to write a plot summaries using only the commonalities between two books/movies. This is so common because if you haven’t actually read the original works, it sounds like one’s a complete rip-off of the other. When you have read them, it’s just a cute gimmick.

        • void space says:

          If true, it looks more like case of Sheldrake’s “morphic resonance” than anything plausibly biological. How the fuck could your genes “know” how to name the dog?

          • gcochran9 says:

            Sheldrake’s “morphic resonance ” is horseshit.

            • void space says:

              Whatever you want to call it, there is something unknown and unexplainable at play.

              • void space says:

                Anyone tried to persuade the two Jims to submit to experiment to prove whether this is case of telepathic bond?


              • gcochran9 says:

                No necessity for it. For one thing, the dog names really could be coincidence. But it’s certainly no weirder than both building a white circular bench around a tree in the front yard. With the same genes, you get extremely similar brains, that like the same things. Drop them in the same milieu, give them some freedom, and they’ll make similar choices – because they like the same things, are good at the same things, etc. Your preferences are your constraints.

          • Alice says:

            But this comment doesn’t speak to the evidence. How the heck could light be a particle and a wave? It’s absurd. How could time and space itself expand? It’s absurd. Yet it is, and it does.

            We don’t understand yet in specific mathematical terms how preferences are encoded in genes. We don’t understand how proteins create a chain of causality to repeatable emotional reactions. But the evidence is piling up that we do.

      • gcochran9 says:

        They both smoked Salems. They both drove light-blue Chevys. One Jim had named his son “James Allan” and the other Jim had named his son “James Alan.” Both lived in the only house on their block.

        Leon Kamin said “These are very ambiguous data that can be interpreted any way you want to.” Complete bullshit, bu he probably couldn’t help saying that. Hmmm. If we could genetically detect the people that are can be convinced by evidence – not everyone, probably not even most people – we could add that to the GRE.

        • Sinij says:

          Why stop at sexual orientation? You can as easily argue that we have no free will to speak of if Jims made so many similar choices.

    • DataExplorer says:

      The one i dont get is they both married women with the same name. We all know that men do not choose women for their names, so that is one crazy coincidence not connected to genetics.

      • albatross says:

        How solid is this story? A lot of stuff that came out of psychology in the 60s and 70s was not super reliable. It wouldn’t shock me if the same thing happened here, and the researchers did a lot of cherry-picking or even making stuff up to get a better story. But I don’t know enough about the original research or how closely it was followed/reanalyzed to know whether this is plausible or not.

        That said, it does seem plausible that there are a lot of random cultural forces acting on people, but that these two happened to end up with almost the same cultural forces (driving stuff like what car they drove and what they named their kids), interacting with the same genetic forces.

      • Steven C. says:

        But maybe parents are genetically predisposed to give certain kinds of names to their children, and thus children with the same name are more genetically similar to each other than to children with very different names. The key would be to discover whether there are common attitudes to certain names by large numbers of people, al least within the same culture and time-period.

  6. MadsCarlsen says:

    There’s an interesting documentary, Twin Sisters, about identical (Chinese-origin) twins, raised apart (Norway and California). They do seem pretty different – the Californian is more out-going and even taller.

    I get the impression that twins reared apart, but in the same culture, will be exactly the same. If the culture is different, then the way their genetics interacts with the world will be different. Adoptive parents matter very little.

    • JayMan says:

      Or they’re just one instance that, in this case, doesn’t mean much in isolation.

    • Young says:

      Twins will have the same genetics but may be exposed to different pathogens or chemical insults in utero or during subsequent development. Becoming a living creature involves many paths to error and it may not take much at the right time to kick someone along an unfortunate path. I did ask two homosexual physicians when they realized they were gay and both said they knew almost as soon as they were self aware, well before adolescence. Perhaps they did or perhaps that is what they wanted to remember, but both are intelligent and honest and they believe it to be so.

      • Mark F. says:

        I had no idea about being gay until puberty hit. 5 years olds can’t feel sexual attraction, so I have no idea what these men were feeling.

        • Young says:

          I don’t know what they were feeling, either. However, in a similar conversation with a female friend, also a physician, she said she knew she was straight, attracted to men, at a very early age, well before puberty. If you don’t mind annoying people, do the experiment yourself and ask people.

          • Anonymous says:

            What about when things are more complicated? Before puberty, I was attracted to various girls in school, including a “crush” on the most popular girl in the classroom, but I would self stimulate looking at paintings or sculptures of naked men. As soon as puberty hit, though, my focus shifted entirely to women.

            I have a vague idea about why this happened before puberty, but I don’t have an MZ twin brother to compare notes with.

        • Frau Katze says:

          Are you saying you’re gay but had not the slightest idea until puberty? That would seem to make sense.

          I didn’t even know about gays existing until my teens. (Things have changed a lot lately,) I’m not gay, but a child doesn’t know.

          Still, a local SJW church (i.e. former mainline Protestant) is holding a two day camp for 6-13 years who have gender identity issues. (And I doubt they’re genetic, like being XXY, but maybe they are, It seems to be politically incorrect to discuss any physical condition,)

          The people running the camp are all people who are “genderfluid” or “genderqueer” or some other such name.

          Parents wouldn’t send a typical kid there, so who are these six-year olds who require such a camp?

          • Young says:

            I think it is possible that sexual orientation is just that: orientation. Early in life for most of us the needle points to the opposite sex, there is interest, curiosity, and probably many other things, but the full sexual attraction comes in with the hormones and surges along a track set down much earlier.

            • Dan Bagrov says:

              You must be new. In this comments section we like to use our brains “for more than cooling the blood”.

              Think about how selection operates on gene frequencies. If a genotype space existed where sexuality could be randomly and permanently redirected toward homosexuality, it have been pruned before the spine evolved and incrementally purged each generation thence. It’s not genetic. No way that works.

              • Young says:

                Didn’t say it was necessarily genetic. I have said something altered the developmental path. How else to explain identical twins having different sexual orientation or gender identity?

              • PhilippeO says:

                It might be connected with Birth Order. if toddler exposed to older brothers (or bigger children in playschool) homosexuality activate, otherwise it dormant.

              • Except that every homosexual male I’ve known well enough to have a conversation with has been able to engage in coitus with a woman (which yes, is the definition of coitus, but still). Many of them either had kids (married for a while), or wanted kids at some point.

                I’m sure there are some (especially younger) homosexuals who never tried to be straight and live a straight lifestyle (marriage family etc), but MANY of those born before (to pick an arbitrary date) 1980 living the “straight” life was the default option.

                “Homosexuality” is a LOT more complicated than just the arrangement of Tab A and Slot B. There are men who engage in many of the same sexual practices as–manual and oral sex, butt play etc. but only with women. There are men who simply do not enjoy the being around women and “bond” only with other men, but have no sexual attraction to those men and relieve their sexual urges either manually, with prostitutes (Men don’t pay prostitutes to have sex with the, they pay them to go away afterwards), or have such a low interest in it that they don’t bother (although I can’t understand the latter).

                Bisexuals–both male and female–make this even murkier. You have people who are sexually attracted to, and engage in intercourse with either sex, and can form emotional bonds with either (sometimes).

                There is some indication that a higher than normal percentage of homosexuals (both male and female) were abused as children–whether this is causal, or there is some indicator that predators sense and home in on remains to be explored.

                There is at least one study ( that indicates (if I read it right) that while the DNA between identical twins is the same, there are epigenetic differences. Again which way the arrow of causation points, I don’t know.

                However I think sexuality and orientation is a LOT more complicated than most of the arguments in either direction admit to.

          • Mark F. says:

            Yes, I’m gay but had no idea I was gay until I was around 15 or 16. I think “gender identity “ is nonsense. Some boys are more feminine, but that doesn’t make them girls. Transgenderism is ridiculous.

            • syonredux says:

              “Yes, I’m gay but had no idea I was gay until I was around 15 or 16”

              You didn’t hit puberty until 15-16?

              • anon says:

                That’s weird. I remember having crushes on girls in first grade.

              • syonredux says:

                “That’s weird. I remember having crushes on girls in first grade.”

                So did (Hi, Alexandra!)I. Of course, the yearning was less palpably physical than it was at 12-13, but I definitely recall having romantic feelings for girls when I was 6-7.

              • gcochran9 says:

                I remember coming home late on the first day of school, because I walked home talking with a young lady I met there. (Hi, Linda !)

              • Ilya says:

                I, too, fell in love in first grade, when I lived in Israel. I was the first Soviet kid in that whole school, back in ’87. Still remember that blond girl’s name (Vered, i.e. Rose). Her parents were well-off Americans (my father would never hire a professional clown to entertain me and others on my birthday). I hard a hard time mustering the courage to tell her how much I liked her. Then a good kid, a classmate of mine (shalom, Shai) gave a new chewing gum and recommended that I offered it to her as a token of admiration. Which I did… Hmm. Just realized: she was only the first J.A.P. I had a bitter experience with.

          • Rosenmops says:

            “I didn’t even know about gays existing until my teens. ”

            I don’t think I knew about them until I was in my 20s. No Internet back in those days. Nobody talked about it.

          • Road to Surfbum says:

            Sounds like parents with Munchausen SBP signaling their woke state.

        • Woof says:

          When I was 8 I found (and stole) my cousins porn stash (sorry Andy). I was very much attracted to the women and completely uninterested in the guys. I don’t agree that we are asexual before puberty, as even at that age I was rather into any female nudity I could observe. Judging by my buddies reactions to my new found stash of Penthouses, they were the same.

          • Mark F. says:

            Interesting. I saw nude women in Playboy when I was around 10 and was totally uninterested. I did see a nude man in a magazine when I was 15 and got excited. But puberty had started by then. I have no idea what my reaction would have been to seeing a nude man when I was 10. I know I felt no sexual desire at that time and did not masturbate.

        • JayMan says:

          5 years olds can’t feel sexual attraction

          You’d be wrong on that point.

    • Frau Katze says:

      The cultures of Norway and California are not that different. Maybe one lived on a farm and one in the big city. That would be somewhat different even in the same country.

      • Dan Bagrov says:

        East Asians would feel enormous alienation in Norway, even in the more multicultural milieu of today. I seen it in east Europeans who grew up there, highly aware their features aren’t consistent with the narrow sampling distribution of Norsk Mr. Potatohead options. Hell, even Swedes feel alienation in Norway. CA would have been much better on that score I reckon, for this individual she-zip’s life experience I mean.

        • MadsCarlsen says:

          In the the documentary, they lived pretty different lives. The Norway twin lived a ‘freer’ life in the sense that she was allowed to roam all over her little fjord town on her own. She seemed more introspective and thoughtful. The Californian was shuttled between air conditioned place to air conditioned place (music school, sports etc) in a car. She seemed more confident, but also a bit more shallow.

          The doc is on YouTube, I recommend it:

        • Dan is absolutely right here. Perhaps in Oslo an Asian child wouldn’t feel quite so out of place, but she would in Norway in general. Yes, they aren’t even all that fond of Swedes, though they think the Danes are pretty much okay. Son #4 is Romanian and lives in Tromso. He has friends and they are very nice to him, but getting dates and getting promoted are hard.

          One would be exposed to different pathogens in Norway and California. I don’t know if that is significant.

          • Frau Katze says:

            Perhaps Norwegians are still angry that Sweden was trading with Nazi Germany, while they were invaded and suffered from the Germans using scorched earth tactics when they (finally) withdrew. Denmark was also occupied.

            Sweden finished out WW2 in good condition, while other places ended up much worse.

            In the UK, in Liverpool, where my mother-in-law lived, there was rationing and shortages. Not to mention the bombing. Had to decide between a bomb shelter or under the stairs. Still, the UK didn’t suffer as much as many continental countries.

            They left for Canada in the 1950s and noticed that it was in much better shape, economically.

            • Yes, that’s what I understand. Even up in Tromso they think that, or maybe there especially. Sweden then invested the money they didn’t spend in WWII in improving their shipping and subsidising auto manufacturers – you may have heard of them – and then regarding their economic power as a result of superior engineering and morality.

              My recent ancestors were Swedes, and that side of the family is still pretty insufferable.

            • Jim says:

              Norway was forced to accept Swedish rule after a war between the two in 1814. Norway became independent around 1900. Before 1814 Norway had been part of Greater Denmark for 400 years. Norwegian and Danish are essentially dialects of the same language. Swedish is a considerably different language.

      • Rosenmops says:

        The two pairs of twins who each had one member switched at birth in Colombia were raised in quite different environments–one mismatched pair in the city of Bogota and the other in a remote part of Colombia.

    • albatross says:

      Raised in California vs Norway sure seems like a much bigger difference (culture and physical environment) than two different towns in the same state.

  7. Young says:

    Off topic but you mentioned it in an earlier post: Tropical Gangsters. Finished it but did not think it particularly funny. However, from my own experience I can say that one could easily find similar social pathology in places like Baltimore. Hundreds of millions of dollars and an enormous amount of technical support have been bled into inner cities in the hopes of bringing them forward. Probably there have been some successes, I would hate to think there were none, but for the most part it has been about as effective as billions in foreign aid to Africa. I suppose it makes some people feel good and Mercedes gets to sell more cars.

    • Frau Katze says:

      I just bought the book on Kindle based on your mention. Hadn’t heard of it before,

      • Young says:

        Made me wonder what would have happened if everyone on the Mayflower had been black.

        • J says:

          The Powhatans would have enslaved them.

          • Young says:

            Most likely, but less likely they would even have survived the crossing. It was a rough trip. What I don’t think is that they would have struggled through to create a new society. Half the originals died the first year but the rest planted civilization in the New World. Remarkable.

        • Peter Lund says:

          We sort of have natural experiments about that.

          There were lots of slave rebellions on the plantations in South America where the slaves moved further inland and tried to set up their own societies. When the whites later moved further inland they practically never found any traces of those Black New Worlds.

    • Rosenmops says:

      I see there is now a “Tropical Gangsters II”.

      • Young says:

        Thanks for the update. I may read it later. At the moment my appetite for more examples of Third World degredation seems to be satisfied.

        • gcochran9 says:

          In the first book, I thought that the bit about government ministers refusing to sign aid agreements ( free money) because it would reveal their illiteracy was hilarious.

          • Young says:

            Yeah, that is characteristic. In my experience here attempts to give informed advice were often rejected because they wanted to pretend they already knew everything and, of course, they couldn’t take advice from a white or Asian who had practical experience. We, of course, were often blamed when things went in the toilet as they generally did. You could almost hear the flushing when they left the building with the check in hand.

      • Jim says:

        It must be nice to have a well-paid job in which nobody expects you to accomplish anything.

  8. curri says:

    The famous case of the half-Jewish identical twins, one raised in Trinidad by his father, the other in Nazi Germany by his mother. They were separated at six months of age:

    • gcochran9 says:

      and when they met, in mid-life, they had the “the same neat mustaches and receding hairlines, they were wearing similar wire-rimmed glasses and matching, light-colored sports jackets.” “”We had identical clothes. I got mine in Israel and he got his in Germany. Exactly the same color, with two buttons,” Yufe recalled in a 1999 BBC documentary. “I said, ‘Oskar, you are wearing the same shirt and same glasses. Why?’ He said to me, ‘Why are you wearing same thing that I am?’ “They both read books from back to front, loved butter and spicy food and flushed the toilet before they used it.”

      [“I always thought I picked up my nervous habits from my father – like fidgeting with other people’s rubber bands and pads and paper clips—until I saw [Oskar],” Yufe said in The Times. “He’s the same way.” ]

      As far as brains and personality, again the same guy twice.

      • Sinij says:

        If two identical computer programs given the same inputs produce the same output, is that output could be considered a choice? If I were given an opportunity to relive my life 1000 times, would I make the same choices 1000 times?

  9. jb says:

    But aren’t the “Jim twins” unusually similar, even for identical twins? My understanding is that while MZ twins are on average much more similar than DZ twins or non-twins, there are still plenty of individual cases where they aren’t really all that similar; i.e., where they are easily told apart physically, and have somewhat different personalities and interests.

    I remember reading an article written by someone who worked in a clinic where they did gene testing. Occasionally pairs of twins would come in who had been told that they were one kind of twin but wondered if they might actually be the other. And in every single case, if a pair of twins had been told they were fraternal but suspected they might be identical, it turned out that they were in fact identical. (The supposedly fraternal Olsen sisters might want to consider taking such a test). The takeaway is that there are a fair number of MZ twins who are sufficiently dissimilar that their monozygote status isn’t overwhelmingly obvious to everyone.

    • gcochran9 says:

      If even some identical twins raised apart are effectively the same guy twice, you have to suspect that environmental influences or insults have to be fairly strong to have much effect. Because every such pair is exposed to some environmental differences. Apparently below some threshold, they have no effect.

      I knew a couple of sets of identical twins growing up. I couldn’t tell them apart.

      • Frau Katze says:

        I too knew a pair of boys I couldn’t apart. Non-family called one of them “hey, Chris or Paul.”

        Another pair of middle aged men I know are likewise impossible to tell apart, except one has Parkinson’s and the other doesn’t.

      • Young says:

        Interesting case related in “Becoming Nicole”, one twin normal, the other twin transgender from early in life. Oddly, the transgender twin was much better at sports than the normal male, much to his annoyance–his brother is a girl and can swing a bat better than he can. Something kicked the one off the rails during development and it was not social environment since the twins we raised together.

      • gkai says:

        It would not surprise me that some genome are much more sensitive to nudges than other, so the effect of environment may be quite different on 2 different MZ pairs.
        In particular, I think I remember reading (here?) that genetic load makes development less robust…Then loaded MZ would tend to be more different than less loaded ones…
        Would makes sense imho, and when they showed MZ twins on TV you always find some much more alike than others. Maybe some misdiagnosed HZ explain part of this, but I do not believe it explains all…

        • gcochran9 says:

          Or, some have been thumped and others have not.

          • gkai says:

            Could be, could be….but if thumping significant enough to visibly affect MZ is so common, environmental effect is back, and Jim twins had indeed both same genes and same environment (defined as have been thumped the same way).
            This is a blow to the thesis that the significant thumps are severe physical abuse…only remaining thumps would be pathogens that do hit MZ somewhat randomly but often, are considered benign or even silent at the moment, but still affect development strongly. Doubtful…

            • P. K. Adithya says:

              I think Dr. Cochran’s point is that environmental effects do show up, but there is very little evidence that the kind of environmental effects we most want to be significant (family environment, schooling, peer groups) are indeed so.

              • albatross says:

                Civilization is basically all about finding ways to minimize the things that want to thump our kids in bad ways. Everything from civil engineering (good sewers and safe water) to public health (vaccines and getting rid of lead paint and adding iodine to salt) to protection from physical danger (cops and soldiers, traffic laws, building codes) is lined up to minimize the stuff that could screw up your kids in some unpleasant way.

                And in Western societies, we also have a big emphasis on personal freedom and the ability to be yourself. Which probably makes genetic/inborn tendencies much stronger. I was reading myself (simple) science books when I was five years old. Shockingly, I still read science books now, just better ones. If I’d been born a Chinese farmer during the Cultural Revolution, or a slave on a West Indies sugar plantation, or a Russian serf in the 1600s, my inborn tendencies wouldn’t have mattered that much, even if I’d somehow dodged all the “thumps” that life would have thrown at me. I would have mostly done the stuff I was allowed or required to do, and my divergence from my neighbors would have been much more limited. The smartest serf in the village is still a serf.

      • Dividualist says:

        One of my friends non-twin younger bother purposefully did the opposite in everything as him to set himself apart / be more individual and perhaps out of competition and a bit of spite as well. It is not hard to think that when identical twins are raised together i.e. normal family, they might do this. I think I would, because I would hate if people would think of me as one of those two. So from this logic, identical twins raised together may become purposefully different, while those who are raised apart and do not know about each other, not.

      • jb says:

        It would be interesting to know more about the actually statistics of twin similarity. Are the dissimilar twins simply the tail of a normal statistical distribution, or are they wild outliers that skew the average away from what it really ought to be?

      • J says:

        I went steady with a nice&smart girl who had an identical twin. They dressed differently so they would not be confused. She gave me few opportunities to meet her sister. Hi Rachel!

        • mtkennedy21 says:

          I knew a pair of girl identical twins who went to different colleges (USC and Stanford) to have separate lives but one Christmas vacation they switched on their dates. The guys finally figured something was wrong but still did not get it as they did not know that the girls had a twin.

      • JokerMan says:

        And now beat one of those twins up when he is a child. Use double binds on him. He will be mentally damaged, and the other one will not be. That’s why you should always love your children. BTW, I do not deny heritability of iq, behaviors, preferences and so on. But you are totally wrong on mental illness. We know, e.g. that stocky people have a tendency towards depression and mania, but it much easier to be treated than in a long and lean person (no joke). When a long and lean person is depressed, it is usually a more severe problem. Schizophrenia is vice versae, probably because these people are more “inward” looking and words and thoughts can mess up your mind in major ways, especially if not spoken out to other persons. Muscular people have a tendency towards paranoia. The pathological states are still triggered by the environment and lifestyle and could be prevented more easily if society would be educated about that and would be more alert of children developing mentally abberant thoughts.

        • gcochran9 says:

          Probably not. For example, if a really nasty environment materially increased your chance of being crazy, what about having half your siblings die before adulthood? Not at all unusual in the past. What about having your city burned to the ground – why weren’t the Japanese full of crazy after WWII? Why weren’t the Ukies disproportionately crazy after the Holodomor?

          The only examples I do know of environment making a big difference involve prenatal starvation, which apparently doubles the risk of schizophrenia. Then there’s tertiary syphilis.

          The best way of explaining the long dominance of environmental explanation of mental illness – which never, ever led to anything useful – is that the psychiatrists themselves were crazy. Or grifters.

      • Harold says:

        My best friend at school had an identical twin brother. I wasn’t friends with the brother; he was colder and harder, less jovial. They were easy to tell apart because one had extensive burn scars.

    • Warren Notes says:

      Both Olsen sisters have a common preference for older men – up to 20 years older.

  10. sprfls says:

    Check out “Three Identical Strangers” (in theatres now). I hesitate to comment on it because, despite being a documentary, it plays out like a mystery/thriller. I even hesitate to link the trailer as they tend to reveal way too much these days.

    Might make for a good Greg Cochran film review. 🙂

    • jb says:

      I saw that film recently in a theater, and even though I knew what it was about I was still surprised at how good it was.

      I’ll note that the subjects were interviewed for the making of the film, and even though the similarity was obvious it was still quiet easy to tell them apart visually. The film makes the point that they didn’t have identical personalities either. Lawrence Wright, author of Twins: And What They Tell Us About Who We Are, was involved in the making of the film, and towards the end he states that he believes that nature and nurture are “close competitors” in influence. Isn’t that the common wisdom nowadays anyways (at least in the field of behavioral genetics): that most traits are roughly 50:50?

      • jb says:

        I’ll also note that in the film Wright comes across as a WASP who very much has his act together both physically and intellectually, and that for me at least he stood out as a quite different sort of person from anyone else in the film. Interesting.

        • Jacob says:

          I don’t want to spoil the movie for anyone else, but jb is right. The cultural and cognitive backdrop of the people involved in this was as interesting as the plot itself.

      • Jacob says:

        Some of the unshared environment is probably just measurement error- might be worth looking at the correlation between test-retest correlation, and additive heritability. Or Cronbach’s alpha and additive heritability.

        Twins aren’t as perfect a model as many think; they have unrepresentative prenatal environments, and in the case of monozygotic twins they can be mirrored. The use of dizygotic twins can control for the former effect.

        I think it really depends on the trait though. Some are more heritable than others.

  11. matt66 says:

    This is your best most refined version of this argument yet, but I’m still not convinced.

    This maybe ignorant but maybe with twins it’s something really dumb, like position of the fetus in the womb. Like maybe hormone distribution isn’t uniform and even gravity is a potential confound. Also, this fits with my understanding is that most of this happens in-utero.

    Maybe the threshold for affecting a pregnant woman’s hormone release isn’t that high. So if it’s pathogenic for the mother during pregnancy, it might be much worse in the modern world. We get more colds and flus than hunter gathers, who interacted with many fewer people.

  12. rien says:

    I like the drops in the basin analogy… => people in society

  13. Noname says:

    Homosexuality is not really different from other paraphilias, except that it was useful in culture wars, so it was built into a “sexual orientation” and now gets celebrated. Men tend to be more strict in pursuing their paraphilias than women.
    The most common explanations for all paraphilias are prenatal developmental errors or an intense early childhood experience that becomes associated with sex.
    I like the second explanation better because it is ironically freudian. Also, there is something very infantile about paraphilias that makes it possible for them to be rooted in childhood experiences: a spanking creates a BDSM practitioner, potty training creates an attraction to body waste, Disney movies turn someone into a furry etc. Were there even so many furries before?
    The explanation could actually be a combination of both factors: a developmental error creating the possibility of paraphilia and an experience creating a form of imprinting that determines the specific type of paraphilia.
    I’d be curious to see how the gay germ theory could explain all the varieties of paraphilias.

    • West Anon says:

      > Homosexuality is not really different from other paraphilias

      It is different because it’s binary. If it was like the others, we’d expect a lot more mixture forms, i.e. bisexuals.

      • Irate eye rater says:

        It also doesn’t correlate with other paraphilias the way paraphilias tend to. These things cluster, if you have one you’re more likely to have another, but homosexuals aren’t any more likely to have them then the populace at large. The gay sex scene gets pretty crazy, but not more than you would naturally expect from a community where everyone is a possible partner for everyone esle, everyone has a male sex drive, and no one can get pregnant.

        The different types of transexuals are a clue. The early onset type, who seem like they might be homosexuals only more so, don’t have any more paraphilias than anyone else either. The late onset type who are driven by autogynophillic sexual urges do have more. A lot more, as if they all already have one.

        In AGPs, and paraphilia-havers generally, the sex drive is the root of the issue. Something has gone screwy there and now it sexually targets all kinds of crazy things.

        Homosexuals, transgender or otherwise, don’t look like that. Their sex drives keep their eyes on the balls, as it were. The targeting is perfectly functional with the sole problem that its pointed at the wrong gender. Whatever the issue is, its upstream of the sex drive itself.

        • Noname says:

          Why do you think that classic gay attire was black leathers and studs?

        • Cloveoil says:

          I’m not sure: paraphilia seems to correlate with a high IQ, tendency to boredom, and curiosity. You will remember reading that typically AGPs are high IQ and HSTS aren’t. I think there’s your answer.

          • Irate eye rater says:

            I could believe lots of smarts leaves the brain vulnerable to other problems. Any time you optimize for one thing really hard other things get pitched over the side. Greyhounds are fast, but they have lots of weird health issues you dont see in other dogs.

            That really just goes to reinforce my point though. HSTS, and more bog standard gays, don’t mesh with that paraphilia profile. Something else is happening.

          • Warren Notes says:

            Putting aside paraphilia and the historical fashion trends of gay sub-cultures for a second, what about conceptualizing homosexuality in terms of a brain disease? Take the most stark example psychiatry and psychology have of brain disease – schizophrenia. I don’t tend to think of that as “binary,” and in an evolutionary sense, it doesn’t facilitate reproduction – word salad or catatonia do not a lady-killer make.

            Question – could the existence of a gay pathogen be investigated using methods described by Gong, Chen Yang and Tsao in their article “A Next Generation-Sequencing Analysis Pipeline for Detecting Unknown Pathogens from Mixed Clinical Samples and Revealing Their Genetic Diversity”? And could the viral loads of identified pathogens identified in gay versus straight samples provide a strong lead for the existence and identify of the pathogen, if it does exist?

            • Warren Notes says:

              Sorry – meant to say that I DO think of schizophrenia as binary.

            • gcochran9 says:

              Thinking of homosexuality as some kind of brain disease is certainly correct: analyze it in terms of fitness. a Darwinian disease.

              Might work. Some things might be hard to detect, because of effects that show up considerably later. Like, I don’ think that people with rheumatic heart disease have a continuing strep infection.

              • saintonge235 says:

                I’ve recently been given reason to think that “homosexuality” may not be a Darwinian disease in many cultures.

                Anthropologist C. R. Hallpike has written that in most of the primitive societies in the anthropological literature, the pressure to marry and have children is so great that everyone has about the same average number of children, regardless of any sexual preference.

                It’s only in cultures where the pressure to marry is resistable that “homosexuality” becomes a Darwinian disease.

              • gcochran9 says:

                In most hunter-gatherer societies, they’ve never even heard of homosexuality.

      • Noname says:

        You are just making up rules, now.
        Lesbians exist only in male fantasies and as a political identity, almost all of them are bisexual. “Lesbians” have more male partners than the average straight woman.

    • jb says:

      I’ve believed for a while that any explanation for homosexuality needs to be able to explain other paraphilias as well. I’ve even argued so on this blog.

      In particular, I think that primate sexuality may be more fragile and easily derailed than sexuality in other mammals, because is other mammals it’s rooted in the sense of smell. Male dogs for example go crazy when they can smell a female in heat. Primates (or at least apes, and certainly humans) have lost that deep ancient mechanism, so they’ve needed to jury-rig a replacement, probably one based on their primary sense, sight. It works fairly well with chimps and gorillas, who live a predictable sort of life, but humans are flooded with all kinds of bizarre stimulus, and I think this sometimes just knocks the whole thing sideways.

      In this hypothesis homosexuality would be the most common paraphilia because the opposite sex is everywhere, and there are so many opportunities to get confused. Other paraphilias would be triggered by early childhood experiences that were more random and unusual, so they are correspondingly less common. There may well be genetic influences as well, but I think a unified field theory of paraphilia will look something like what I am suggesting.

      • Noname says:

        The existing data is pretty scarce, but it looks like BDSM is far more popular than LGBT. It is hard to distinguish between those who try something they read in 50 Shades and those who need this stuff all the time, but the numbers are pretty big.

        • jb says:

          Really? That would be interesting to know for sure.

          Although kids used to get spanked an awful lot, and these days (and probably from the early days of TV) they are exposed to all kinds of violence and stressful situations on screens of various sizes, so there are still plenty of opportunities for confusion.

          • albatross says:

            I have this really creepy thought that our psyches somehow want to maintain some evolved-in set-point of fear, domination, pain, etc., and thus as society becomes nicer and safer, BDSM becomes more common. (And probably other stuff–anorexia, self-mutilation, crazy risk-taking behavior, etc.)

            • gcochran9 says:

              I guess I got beat up enough in school to entirely avoid that trap.

            • Murder mysteries sell far better in places and among tribes where actual homicide rates are very low. It’s not accidental that sales are better in England than in Scotland and Ireland, or in the US states that border Canada than in, say, Louisiana.

              • Toddy Cat says:

                Real murder isn’t that interesting, or fun, and people actually exposed to it tend to know this. It isn’t usually Lord Hailworth’s butler killing Lady Parker in the loo with a five iron over an ancestral slight; it tends to be DeShawn shooting Trayveen over Nikes right in front of a cop. As noted, not very interesting or entertaining.

              • albatross says:

                I always wonder about the “dark underbelly of society” sorts of stories. It seems plausible that they’d be more fun to watch in Geneva than in Mexico City. In Geneva, the dark underbelly of corrupt cops and mobsters probably doesn’t impact your life much, whereas in Mexico City it’s a constant background worry.

                Alternatively, I like reading war stories, but maybe if I’d actually ever been in a way, I’d find them too upsetting to read. I had a relative from Croatia who rode out most of WW2 in Austria as a teenager. I knew her in her 70s and 80s, and even then, she wouldn’t watch coverage of wars on TV.

  14. West Anon says:

    Fun homosexuality fact found on wikpedia:

    “… it was found that male rats treated with an aromatase inhibitor showed a partner preference for females when tested in the late dark phase but showed homosexual mating preferences when tested in the early dark phase”

    Oh, so that’s why the ancient Greek had loverboy over for dinner before hitting the sack with the wife: A culturally acquired taste for an obscure bitter herb containing an aromatase inhibitor.

  15. Steve in Greensboro says:

    Charles Murray comes here to help organize his inchoate thoughts. Me? I come here for the Firesign references.

  16. Cloveoil says:

    What interests me is that innate and faculative homosexuality are both real, but neither is constant in time and place. Why?

  17. Denis says:

    The imprinting theory is the most plausible ones. After all male rams start to get interested in goats if raised exclusively in this company. That would match with much higher rate of male kinkiness in general as well

  18. Smithie says:

    I understand the majority of identical twins share the same placenta, but have different amniotic sacs. That makes me wonder how robust the amniotic sac is as a barrier to infection.

    I wouldn’t guess it is a particularly good barrier by looking at it, but I’m more familiar with the anatomy and physiology of the blood-brain barrier and the placenta.

  19. Jacob says:

    Do we know much about personality in mirror twins? That could artificially reduce personality heritability estimates, if some of the hemispheric neuroanatomy is affected.

    I met an identical twin recently who took an environmental policy major in Oregon, while her twin took a computer science major in Massachusetts. She said something or other about them having different personalities.

    I saw her writing with her left hand and asked if her twin was right-handed. She was shocked that I was able to guess it- yes, it just so happens that her twin is right-handed.

  20. Whitney g says:

    Okay, I’m just going to throw this out there. I worked in restaurants for 20 years and for about 10 of those years I was what was known as a “fag hag”. So I was surrounded by homosexual men for decades and out of curiosity I started quizzing them at some point. And in all those years I never met one homosexual man that had not been molested as a child. It’s a particular group of restaurant workers but it’s still in the hundreds

    • This is generally known by both gays and straights, but cannot be acknowledged between them.

      It isn’t 100% BTW. Just lots.

    • TB says:

      I suspect a certain amount of imprinting goes on. I grew up in an area with lots of Scandinavians, busty blonds everywhere and I loved it. But my first real experience was a skinny brunette. Married a skinny brunette, and pretty much never dated anything else.

    • Rye says:

      Here is a study which corroborates your observation.

      It seems to me that Greg is hinting at some very disquieting conclusions. If homosexuality is caused by behavior-altering pathogens, then homosexuals are akin to zombie ants, uncontrollably compelled to maximize the spread of their pathogen. If so, then homophobia must be an evolved response to this pathogen which varies in populations according to history of previous exposure.

      The most effective means to spread this pathogen would be for infected individuals to form cliques and infiltrate social positions which grant access to children. Homosexuals would also become preferred employees in many institutions, due to the mobility and flexibility of their labor. The course of our society in relation to these issues suggests that thusly infected individuals have disproportionately high representation among our elites. If Greg is correct, then it may be the case that the directives which drive a substantial part of our elite are generated from the genetic code of a parasite. When an individual suffers severe social repercussions for actions and expressions which are contrary to the interests of the pathogen, this can be modeled as retaliatory action by a non-human organism which has conquered us. Reality may be stranger than science-fiction.

      • Tl Howard says:

        If this were the case, I’d think a candidate parasite would have been found by now in those gay rams since the researcher hasn’t been handicapped by not being able to dissect their brains.

        ps–sorry if this posts several times, having trouble posting

      • HenryScrope says:


        • J says:

          Yes, but plausible. Parasited mice gets high on cat piss smell and seek to be caught and eaten. Parasited ants that climb the grass and wait to be eaten by the cows.

          • Matt says:

            What a hilariously stupid comment. Most gays who were in fact “molested’ were done so when they were teenagers. Visibly feminine and approached by an older male. Zietsch et al. used a representative study and found a rate of childhood sexual abuse among male homosexuals of about 12% before age 12. You have to be on another planet if you think we wouldn’t have noticed masculine boys suddenly becoming little faggots after being turned into a zombie by a germ. If its a germ, it’s not transmitted sexually and it doesn’t behave like that.

    • Young says:

      Interesting account and it left me wondering how many of these men signaled they were interested in male attention when they were children. Many may have done if sexual orientation set early even if they were not quite sure what it meant. In essence, some and maybe many, of these early encounters were not molestation in the sense of being fully forced. There may have been some willingness to explore on the part of the child. I don’t think that the encounters converted them to homosexuality; they may already have been on the path. In fact, I knew of straight males who as minors exploited homosexuals for favors and did not have their heads turned because of the experience. They did strike me as being rather cold people, though.

  21. Tl Howard says:

    “Usually when a guy is homosexual, his identical twin is not. Family environment doesn’t look to be the cause: something thumped the homosexual twin.”

    If it’s pathogenic in origin, what about a virus that is not only omnipresent but also one to which kids don’t develop immunity, one that can hit them two, three, even four times from infancy through childhood? In other words, some kids can get hit to the point of receiving a “thumping”?

  22. void space says:

    Are there any studies on animals? How similar are cloned sheep or cattle raised apart (as far as sheep and cattle have personality, customs and hobbies 😉

  23. David Chamberlin says:

    Cochran says “environmental influences people want to exist mostly don’t.”
    He’s right and we don’t have to look at the similarity in identical twins to see this, although it is proof in and of itself. “The heritability of intelligence increases from about 20% in infancy to perhaps 80% in later adulthood,” which sounds weird but it is what multiple studies confirm and makes sense if and only if environment has little effect effect. If environment was very important differences between siblings or twins would increase with age not decrease.

    • albatross says:

      Sort of. Environmental influences that have big impacts are also the ones we’ve mostly figured out how to optimize in first-world countries. Think about malnutrition and infections and environmental toxins (lead) and deficiency diseases and extreme abuse or neglect–those are all things that every decent society actively tries to prevent for their members.

      This isn’t failure, it’s success–if most kids in our society were starving and infected with a dozen kinds of parasites and ate lead paint chips off the walls and never made it inside a schoolhouse, the heritability of intelligence and height and such would be much, much lower.

  24. void space says:

    No necessity for it. For one thing, the dog names really could be coincidence. But it’s certainly no weirder than both building a white circular bench around a tree in the front yard. With the same genes, you get extremely similar brains, that like the same things.

    Yeah, right. Show me the gene for building white circular bench. Show me the gene for naming dogs and children. Show me the gene for buying car of exactly the right shade of blue. If this uncanny twin resonance is of genetic origin, why it does not show on every twin pair?

    I well understand that 99,99% of “paranormal”, “psi” and “miraculous” phenomena is BS, but I understand that all that we know is just microscopic bubble in the infinity of unknown.

    Click to access Parker2013.pdf

    • Jim says:

      Of course there is also no gene for digestion and no gene for walking and no gene for breathing and no gene for sleeping. So we can conclude that digestion, walking, breathing and sleeping are purely learned cultural behaviors with no basis in our polynucleotides.

    • Jim says:

      I should have added “eating” and “drinking” as examples of human behavior “there is no gene for”. So genetics cannot have anything to do with explaining why people eat and drink. It must be purely cultural.

      • void space says:

        Do not be obtuse, and show me any plausible mechanism how could “genes” make me name my dog Toy and son James Allan. Where are “Toy” and “James Allan” encoded in DNA?

        • albatross says:

          What TV shows do you like? What kind of music? What movies? What books?

          Do you suppose genes play a role in any of that? Because if they do (surely they do), then downstream, you’ll see stuff like what names seem reasonable for your son, or even what sort of thing you might think to name your dog. I mean, there’s still a lot of coincidence there, but the pool of names for a kid that occur to you as an adult has a lot to do with the books and movies and such you have consumed, as well as your surrounding society. It’s not like the genes would make you name your kid James Alan, but the genes might make you like a certain kind of movie, and that might lead you to have the lead actor’s name in your head when you’re thinking about names to give your kid.

        • jb says:

          I think the mechanism is selection bias. Out of the huge number of possible coincidences, the few that actually happen are noticed, while the ones that don’t happen are not. The connection to identical twins is that the psychological similarity of a pair of twins would make such coincidences much more likely.

          For example the odds of you and me choosing the same names for our sons and dogs might be 1/1,000,000, while for twins the odds might be 1/10,000. Still very low, but summing over all possible coincidences such differences would give you a much higher chance of seeing something freakishly unlikely with twins than with two random unrelated people, or even siblings. The many non-coincidences will of course pass unremarked.

          • gcochran9 says:

            I’s a lot more likely than that. Reminds me of the time a friend read a satirical piece about how neocons were probably from the Phantom Zone, though it funny, was about to tell me to check it out, and belatedly noticed that I had actually written it.

            • jb says:

              I was talking with my brother’s wife about something a few years ago, and I referenced an old TV commercial that I found especially funny. She laughed and said my brother had thought that particular commercial was the funniest thing he had ever seen, and joked about it for weeks after it first came out. It’s an amusing little commercial, but I doubt everyone finds it as funny as we both did.

              (She also says we have the exact same boxy little feet. Which we do).

          • pixelwight says:

            The odds are way higher (better) than that. There might be 1000 different names for boys and dogs, but there’s a handful that are very popular, and there’s a strong cultural drift, too. Through the 1960s, the top 20 names covered 33-50% of all babies born. Today, that fraction has fallen to 1/8th of all babies, but that’s still very high.

        • Jim says:

          When Darwin wrote “The Origin of Species” he did not have the slightest clue of any mechanism to explain how anything could be inherited. But he could certainly know that many things were at least in part inherited. The behavioral similarities between identical twins such as what styles of clothing they prefer are sufficient to show that genetics plays a role in such things even though we cannot give any detailed explanation.

        • Jim says:

          To know that a trait is inherited it is not necessary to know anything whatsoever about the mechanisms producing the trait or the mechanisms causing the trait to be inherited. Back in the middle of the 19th century Darwin knew that the ability to conduct photosynthesis was inherited even though 1) Darwin had not the remotest clue as to how photosynthesis was accomplished and 2) Darwin had not the remotest clue as to how the ability to conduct photosynthesis was inherited.

    • Cloveoil says:

      Or the right wing’s version of blank slatism? This is too good to be true. 😉

  25. Frank Messmann says:

    About a half year ago the New York Times wrote about a scientific photographer who developed an algorithm which could predict with great accuracy who was a homosexual. Given 5 photos, he could predict w 90% accuracy. This means that genes were not the cause. Something happens in utero.

    • gcochran9 says:

      Why necessarily in utero? Answer: no reason.

      • Phille says:

        Because some homosexuals show feminine behaviour and show that behaviour very early. A sensible explanation for that is that they have non de-feminized brains. And defeminization happens in utero.

        • Toddy Cat says:

          “Given 5 photos, he could predict w 90% accuracy”

          Wouldn’t that indicate a genitic cause? Given five pictures, I can pick out the black guy 100% of the time, and that’s not in utero…

        • Tl Howard says:

          I thought the most recent research suggested the defeminization also occurred perinatally, shortly before and also after birth.

      • David Chamberlin says:

        Not true. Multiple studies have shown an increase in the chances of being a homosexual man increases with each older brother you have.
        The older brother effect increases the chance of a boy being homosexual by 33% for each older brother a boy has. This is likely due to changes induced in the mother’s body when gestating a boy that effects subsequent sons.

        On the other hand there is no reason to believe homosexuality is caused by a pathogen.

        • David Chamberlin says:

          But the older brother effect accounts for only one fifth of the homosexual men but it is a clear indicator that a cause of homosexuality is a developmental issue. It can’t be genetic for obvious reasons discussed many times here and I seriously doubt if an infectious agent has any thing to do with causing it. Multiple variables must be responsible but I find it highly unlikely that it can be disease related. Nothing has been found yet that indicates any way that could happen. It still could be but I find that highly improbable. But betting against Cochran is like betting against Vegas so ……maybe.

    • Young says:

      An aside, the linked article refers to the Theban Band, an elite military unit composed of homosexuals. Couldn’t remember the name when I mentioned them above and I also incorrectly said they were wiped out by Alexander when, in fact, they were destroyed by his father, Philip II, though I think Alexander was present. Didn’t intend to mislead.

  26. Cpluskx says:

    Is it possible that when a very feminine man and woman have a male child he’s more likely to be gay and a very masculine man/woman have a female child she’s more likely to be lesbian or this is a stupid hypothesis?

  27. Young says:

    Edward II fathered Edward III, so I doubt your idea works. Besides, there is still the problem of identical twins, one of whom is homosexual and the other not.

  28. Pingback: Nature Utterly Pwned Nature – Brave Ole World

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