Thursday, July 24, 2008

Are the children of first-generation immigrants more likely to be autistic?

I've known about this for about a year, but I never got around to writing about it. I was reminded of it by a recent David Kirby post where he informs us that "an unusually large proportion of Somali-speaking children in Minnesota have autism." I suppose David Kirby is trying to make this about vaccines. The thing is that a link between autism and immigration has been suspected since at least the 1970s, even though it apparently never became an area of research that interested many investigators. Let me just quote from some abstracts, in chronological order.

Harper & Williams (1976): "In a survey on the occurrence of infantile autism in New South Wales it was found that 21-9% of children had at least one foreign-born parent whose native language was not English."

Gillberg et al. (1987): "Urban children with autism more often than age-matched children in the general population had immigrant parents from 'exotic' countries."

Gillberg et al. (1995): "The prevalence for autistic disorder in Göteborg children born to mothers who were born in Uganda was 15% which is almost 200 times higher than in the general population of children."

Gillberg & Gillberg (1996): "Fifteen of these children (27%) were born to parents, at least one of whom had migrated to Sweden."

Bernard-Opitz et al. (2001): "Discussion focuses on possible risk factors and psychosocial adversities for autism such as a high frequency of caregivers who are foreign maids, the use of multiple languages and the high level of punitive educational practices."

Lauritsen et al. (2005): "An increased relative risk of 1.4 was found if the mother was born outside Europe, and in children of parents who were born in different countries."

Maimburg and Vaeth (2006): "The risk of infantile autism was increased for mothers aged >35 years, with foreign citizenship, and mothers who used medicine during pregnancy."

Kolevzon et al. (2007): "The parental characteristics associated with an increased risk of autism and autism spectrum disorders included advanced maternal age, advanced paternal age, and maternal place of birth outside Europe or North America."

There are reports along these lines from Canada as well. In fact, this was discussed in Interverbal's discussion of critiques of Fombonne et al. (2006).

Now, the first thing we need to ask ourselves about these findings is whether they document an actual phenomenon or an artifact. Is there a confound that explains the apparent association?

But if in fact there's an association, what explains it? We don't really know. You will find some unsubstantiated speculation based on old ideas in the cited abstracts, some speculation that I'm sure many readers will find objectionable. It's not surprising to find these types of explanations in old papers, though. If I may engage in some speculation of my own, based on newer ideas, I would say that maternal stress during gestation – see Kinney et al. (2008) – cannot be discounted.

Finally, I'd like to bring attention to Roberts et al. (2007), a study claiming to associate autism with proximity to agricultural pesticide applications in the California Central Valley. The authors stated that they could not dismiss the possibility that the women studied may be disproportionately employed in agriculture. It just so happens that immigrant women also tend to be disproportionately employed in agriculture.

29 comments:

  1. Very interesting that this seems to happen even in other countries. My first thought is that maybe cultural differences between the immigrant family and the host country contribute to kids of immigrants being more likely to be perceived as socially inept. Surely the researchers must have thought of this, though - I must admit I didn't take time to read even the abstracts of the papers you listed.

    ReplyDelete
  2. I wonder if the genes involved in autism also tend to make people more curious about the world and more willing to migrate, in much the same way that autistic children often wander away to explore.

    It is an interesting question, indeed.

    ReplyDelete
  3. I hadn't considered either of your explanations, Isles and Abfh. I wonder if researchers will be interested enough in this matter to pursue it further and figure it out. Maybe they'll get to it when they are no longer busy debunking the anti-vaccionists :)

    ReplyDelete
  4. An alternative theory examining the cause of autism is available here http://www.neoteny.org/?cat=7. It details why mixed heritage and immigrant populations are particularly vulnerable to variations in mother's testosterone levels increasing males progeny maturational delay, and maturational delay in the children when the parents have had few common ancestors in the past 10,000 years.

    ReplyDelete
  5. My thought would be that it's simply that autistic children of immigrants have a harder time passing than autistic children of non-immigrants. Parents familiar with the local culture can help their children figure out what they would miss on their own.

    ReplyDelete
  6. Also, if it's hard for an autistic child to deal with one language, imagine what it must be like if they had to deal with two. I would think this not only makes the speech aspect of the child's autism more noticeable, but it could also be a lot more stressful to the child in school situations and so forth.

    Bilingualism can be an problem for non-autistic kids too. It's hard to imagine it's not a problem for autistic kids.

    ReplyDelete
  7. I'm a hyperlexic Aspie first-generation immigrant. I came from Germany to the United States when I was six and was fluent in English by the time a few months had passed. No language problems here.

    However, there's still the cultural differences. Learning culture is difficult for me; and growing up with one culture at home and another at school means twice as much to learn.

    I was autistic as a small child in Germany; and I am still autistic here in the US.

    But someone who is very, very borderline, someone who might be diagnosed with mild Asperger's, might have just enough extra difficulty living between cultures for his traits to cross the "diagnosis" line.

    Most likely, the rest would have been autistic no matter what... but the very mild cases might be influenced one way or another by the 5% of any Spectrum condition that comes from non-heritable factors.

    ReplyDelete
  8. I was wondering if there has been a comparison of autism rates between those with mixed heritage and those with both parents from a foreign country. The only genetic studies that I've seen look for bad genes. All the genes could be good ones, but one or more genes could cause difficulties because of other genes in the "environment" of the body. The immigrant issue sounds like one that might lead to greater understanding of autism.

    ReplyDelete
  9. Interesting idea. I am going to field a semi-random guess here and ask a simple question. Isn't it possible that the childeren involved are not actually autistic in genetics but may simply be so overloaded at an early age that they show signs of autism? I had problems visiting Mexico for eight day and I was 15, i think. Imagine someone at five being moved and getting a culture overload.

    It might be a good explanation.

    ReplyDelete
  10. Hi Nowhereman. Current thinking in the autism community is that autism is the product of biology (either genetics or some type of environmental influence affecting biology). But you never know. There is something called "institutional autism" which would be a counter-example. They say you can tell it's different to "regular" idiopathic autism. They sometimes call it quasi-autism. But I don't think there's an objective way to tell the difference for sure. It's always problematic (practically and politically) to try to separate autism into types that are "not really autism."

    ReplyDelete
  11. Yes, children of immigrant parents are more likely to be autistic if specifically their parents are from an equatorial region moving to a part of the world with widely varying light or seasons.

    The work of Norman Geschwin describing the effects of light on the pineal on testosterone forms the foundation of this theory.

    Please consider visiting http://www.neoteny.org/?cat=7 to review a unique and unorthodox theory for the cause of autism.

    Originsofautism.com goes into greater detail.

    Thank you,

    Andrew Lehman

    ReplyDelete
  12. Andrew Lehman8/08/2008 6:14 AM

    A child’s lifelong maturation rates are set six weeks before birth by mother’s testosterone levels. A mother with high testosterone births low testosterone males and high testosterone females. A low testosterone female raises high testosterone males and low testosterone females. Numerous factors influence a mother’s testosterone levels including her age, stress, exercise, smoking, alcohol, drugs, diet and light. Radical elevations in a mother’s testosterone level can lead to extreme maturational delay and autism.

    This is part of a larger picture of how humans evolve. Changing maturation rates over generations send societies in one of two directions: matrifocal or patrifocal social structures. Low testosterone males mating with high testosterone females form the foundation of matrifocal social structure. High testosterone males pairing with low testosterone females make up patrifocal social structure. When mothers today exhibit matrifocal features, high testosterone, while exposed to environmental influences that elevate their testosterone further, male children with delay tendencies may shift into extreme delay.

    This theory predicts that females with autism will not exhibit maturational delay, but maturational acceleration accompanied by elevated testosterone. When a mother’s testosterone level elevates, she not only influences the maturation rates of her children, she send them on a journey into the past. Maturation rates unfold on two scales, the scale of the individual unfolding in a lifetime – personal ontogeny - and on the scale of how our species has evolved over the last few thousand generations. We have recently evolved out of matrifocal social structure to patrifocal social structure. We reverse the process by reversing our maturation rates reproducing that path we took to arrive in the present. Elevating mother’s testosterone we instill ancient ontogenetic pathways, propelling our children back in time to when language was still new. For males, backwards is lowered testosterone and maturational delay. For females backwards is raised testosterone and maturational acceleration.

    Light influences testosterone levels via the pineal gland that regulates testosterone production. Testosterone fluctuations of 30% a day can be observed as thresholds follow diurnal cycles, influenced by the availability of sunlight. What happens when a people are shifted away from consistent daily 30% fluctuations into Northern climates where the light in winter is almost non existent, in summer almost always there?

    Jews and Blacks both display anomalous distributions of testosterone in males. Instead of cultures that reflect either matrifocal of patrifocal social structure distributions of testosterone following the patterns noted above, with both Blacks and Jews the males (studies were conducted with only males) showed either very high or very low testosterone levels. Both these cultures were transplanted from equatorial regions to climates with light fluctuating seasons.

    This being the case, one would predict that both these ethnicities would exhibit a higher percentages of conditions characterized by maturational delay.

    Somalis immigrating to Minnesota are discovering radical rates of autism among their children. This theory predicts that autistic children birthdays should cluster in certain times of the year. If mother’s light influenced testosterone rates are particularly high at six weeks before birth, intervention to lower rates (for example staying indoors) would be prudent.

    There is also the possibility that the father’s testosterone levels influence the child’s rates of maturation. There are no studies to support this. It could be estimated at what seasons a fathers testosterone rates are lowest at conception, and compare that to when mother’s testosterone is highest six weeks before birth and look for the impacts of overlap. It may be that both mother and father are having an effect.

    Light and testosterone are related. Many things in our environment influence testosterone levels. Understanding autism involves recognizing how testosterone is influenced and realizing how this connects to how we evolved.

    Visit http://www.neoteny.org/?cat=7 for more detail.

    ReplyDelete
  13. http://www.youtube.com/watch?v=ja6UL6d9y0E

    What else can you say :)

    ReplyDelete
  14. I know this is off topic, but you don't have any other contact option... and we need all the help we can get
    Please help an autistic child who is being retained, and forced to repeat 4K, even though he passed, because his birthday falls 24 days late.
    http://www.thepetitionsite.com/1/due-to-being-born-24-days-late-autistic-child-must-repeat-4k That is the petition site to sign.
    If you have any questions, or want the full story, I am putting up a website hopefully this weekend
    www.pcveracity.us
    Or call me,
    I'm the mother of the child this is being forced upon.
    850-381-9844
    Honestly, you're my greatest hope for help. Reaching out to people on the internet and getting support is our best chance to help my Beau, and prevent this atrocity from happening to other children, who will be equally devastated.
    Thank you for your time,
    Geneva Robinson
    Panama City and Chipley, Fl.

    ReplyDelete
  15. Hi Geneva. I assume you've contacted Kristina over at autismvox.com or Kev over at LB/RB. Those are two of the autism blogs with most traffic.

    Your URL got cut off there. The petition is here.

    ReplyDelete
  16. Andrew Lehman8/26/2008 8:09 AM

    Neuroscientist Norman Geschwin in his 1982 Cerebral Lateralization described the effects of light changes on testosterone levels in mothers, levels that decide the maturation rates of her children.

    The change of light in Somali mothers from their country of origin potentially influence maturation rates, causing autism.

    See http://www.neoteny.org/?p=154.

    ReplyDelete
  17. Thanks Andrew. I think your hypothesis is noted. I suspect the reason no one has commented is that it appears highly speculative and far fetched, to be honest.

    ReplyDelete
  18. It just illustrates again to me the amount of social construction there is in the diagnosis, factors that have nothing whatever to do with the inherent neurological condition of the individual in question but a lot more to do with convention, custom, social class, ethnicity, economic status and a whole lot more that runs not just through the diagnosis of autism but practically every other diagnosis you can think of, it is the elephant in the room which just won't go away, whichever way you look at it.

    Diagnosis is not a pure instrument, it is given by fallible humans in a social environment influenced in there obervations and habits by stereotypes and schemas

    ReplyDelete
  19. Evolutionary theory that concentrates on changes in biology in a single generation is rather rare these days. You have to back a hundred years when heterochony was respected. Combine heterochonic theory with Norman Geschwin's understandings and you have an evolutionary explanation for conditions featuring maturational delay.

    These are not unfamiliar concepts, just unfamiliar to the last four generations.

    See http://www.neoteny.org/?cat=7.

    ReplyDelete
  20. Dr. Geoffrey Rutledge9/10/2008 1:20 PM

    I think your blog is great, and I would like to feature you on the new
    Wellsphere. We feature only the best health bloggers on our WellPages,
    which are special pages that our Health Knowledge Engine crafts to give
    our users answers to their health questions. We would feature you on all
    the pages on topics that our knowledge engine finds are related to your
    blog postings. Because we have over 2 million visitors each month (and we
    are growing rapidly), you would benefit from an expanded audience for
    your writings. If you would like us to feature you, send me an email to
    Dr.Rutledge@wellsphere.com

    Cheers, Geoff

    ReplyDelete
  21. What if, for some reason, mildly autistic/BAP adults are more likely to immigrate, or that immigrant autistic/BAP adults are more likely to have kids?
    Here are some possibilities:
    a) it's easier to relate to someone who can 'explain away' your social misunderstanding and/or odd language as being due to being from another culture, and therefore autistic immigrants are more likely to date and get married than non-immigrant autistics
    b) specifically regarding immigrants from troubled countries, autistic people may be less able/willing to avoid trouble in a volatile political situation, due to things like social naivety, standing out and refusing to follow illogical rules, therefore more likely to have to flee
    c) autistic/BAP people may be more likely to go to college (particularly BAP people) and college graduates are more likely to be granted permission to immigrate because they are felt to be able to contribute more to their new country

    ReplyDelete
  22. "They say you can tell it's different to "regular" idiopathic autism. They sometimes call it quasi-autism. But I don't think there's an objective way to tell the difference for sure. [Regarding institutional autism.]"

    There is. Take the kid out of the instution and look after them properly for awhile. With institutional autism the features disappear soon after being moved into a more healthy environment. A truly autistic kid acts that way in a regular home, too.

    ReplyDelete
  23. Hi Ettina. A regular autistic kid in a regular home could have the same kind of progress, right? It happens, especially at a very young age.

    So no, I don't think there's a truly objective way to tell the difference, biologically or otherwise.

    ReplyDelete
  24. Very good blog, I hope you continue writing and express your thoughts and feelings.

    I like the direction you are taking with your blog. Please don't stop.

    ReplyDelete
  25. How about vitamin D?
    -dark skin, "exotic" origin, nothern latitude, sunblock... wrong diet,rainy/cloudy wether...

    ReplyDelete
  26. Well, mainly because vitamin D deficiency has well known symptoms, and you'd notice these.

    Also, if Somalia is in fact special at the moment, why Somalia, and not other equatorial countries?

    Over at Google Scholar try a search on the mental health of Somali refugees. I think that's more likely to be related to the phenomenon if there's indeed one.

    ReplyDelete
  27. There has been evidence emerging of other equatorial populations, transplanted to Northern latitudes, showing increased signs of autism.

    It's a question of testosterone. What increases levels of testosterone in a mother's womb influencing the maturation rates of her children. Many things effect testosterone, including variations in light.

    ReplyDelete
  28. http://autismadhd.angelfire.com/
    I have a theory that autism is increasing with ethnic diversity. I believe that immigrants are more likely to be ethnically diverse than the general population, please visit my website for more info.

    Thanks

    ReplyDelete
  29. Southeast and main Asian pandora jewelry countries have twisted rubies for centuries, cheap pandora bracelets but research as to where, and how to find more deposits is Pandora charms spare, and production has figured out how and mining companies,” Pandora beads Giuliani says, to look at exactly the right time and place.” pandora set Farther investigation of claret formation, based on tectonic scenery, cheap pandora geochemistry, fluid inclusions and isotopic ratios, allowed discount pandora Giuliani’s lineup to remodel a new prototype for the French Institute pandora 2010 of Research for Development (IRD) and the National Scientific pandora sale Center of Research, two government-sponsored knowledge Pandora Bangles and technology research institutes that aim to aid in the sustainable cheap pandora bracelets development of developing countries. Before the collision pandora bracelets prices of the Eurasian and Indian plates, lagoons or deltas sat in the regions where marble is giant, pandora bracelets and charms he says, “and there is the brains to expect that the new pandora bracelets sale thoughts should help development of the artless capital.” discount pandora bracelets Virginie Garnier, Gaston Giuliani and Daniel Pandora necklace Ohnenstetter urban the shape to do just that. They work for the garnet cheap pandora charms genesis. While studying the bedrock in Vietnam in 1998, the discount pandora charms French players found rubies, which detained traces of aluminum, chromium pandora charms sale and vanadium from universities, international corporations, governments pandora charms 2010 and why the rubies got there, and has created a paradigm Pandora beads to help these evaporites, Garnier says, when the Eurasian cheap pandora beads and Indian plates collided, raising the Himalaya Mountains.

    ReplyDelete