Accidental Brothers

by Dr. Nancy L. Segal

    5.  D. Lieberman, J. Tooby, and L. Cosmides, “The Architecture of Human Kin Detection,” Nature 445, no. 7129 (2007): 727–31.

    6.  E. Burnstein, “Altruism and Genetic Relatedness,” in The Handbook of Evolutionary Psychology, ed. D. M. Buss, 528–51 (Hoboken, NJ: John Wiley, 2005).

    7.  N. L. Segal, Born Together—Reared Apart: The Landmark Minnesota Twin Study (Cambridge, MA: Harvard University Press, 2012).

    8.  N. L. Segal, J. L. Graham, and U. Ettinger, “Unrelated Look-Alikes: A Replicated Study of Personality Similarity and New Qualitative Findings on Social Relatedness,” Personality and Individual Differences 55 (2013): 169–76; N. L. Segal, Entwined Lives: Twins and What They Tell Us About Human Behavior (New York: Plume, 2000).

    9.  J. Ryall, “Japanese Man Born to Wealthy Parents Is Accidentally Switched at Birth and Endures Life of Poverty,” Telegraph (Asia ed.), November 28, 2013, http://www.telegraph.co.uk/news/worldnews/asia/japan/10481091/Japanese-man-born-to-wealthy-parents-is-accidentally-switched-at-birth-and-endures-life-of-poverty.html.

  10.  “Switched at Birth Japanese Man Awarded Payout by Hospital,” Sydney Morning Herald, November 28, 2013, http://www.smh.com.au/world/switched-at-birth-japanese-man-awarded-payout-by-hospital-20131128-2ye0i.html.

  11.  Y. S. Matsumoto, “Notes on Primogeniture in Postwar Japan,” in Japanese Culture: Its Development and Characteristics, ed. R. J. Smith and R. K. Beardsley (London, UK: Routledge, 2004), 55–69.

  12.  J. Mann, “Nurturance or Negligence: Maternal Psychology and Behavioral Preference Among Preterm Twins,” in The Adapted Mind: Evolutionary Psychology and the Evolution of Culture, ed. J. H. Barkow, L. Cosmides, and J. Tooby (New York: Oxford University Press, 1992), 367–90.

  13.  G. Pison, C. Monden, and J. Smits, “Twinning Rates in Developed Countries: Trends and Explanations,” Population and Development Review 41, no. 4 (2015): 629–49; L. S. Forbes, “The Evolutionary Biology of Spontaneous Abortion in Humans,” Trends in Ecology and Evolution 12, no. 11 (1997): 446–50.

  14.  J. G. Hall, “Twinning,” The Lancet 362, no. 9385 (2003): 735–43; K. Kleinhaus et al., “Paternal Age and Twinning in the Jerusalem Perinatal Study,” European Journal of Obstetrics & Gynecology and Reproductive Biology 141, no. 2 (2008): 119–22; E. L. Abel and M. L. Kruger, “Maternal and Paternal Age and Twinning in the United States, 2004–2008,” Journal of Perinatal Medicine 40, no. 3 (2012): 237–39.

  15.  A. Campbell, “Aggression,” in Evolutionary Psychology: The New Science of the Mind, 5th ed., ed. D. M. Buss (New York: Routledge, 2015), 628–52.

  16.  Assisted reproductive technology (ART) has been largely responsible for the dramatic rise in fraternal twinning, but it has also increased identical twinning, although to a lesser degree. Identical twinning rates are between two and twelve times higher with ART, relative to the natural identical twinning rate of .3–.4 percent. K. I. Aston et al., “Monozygotic Twinning Associated with Assisted Reproductive Technologies: A Review,” Reproduction 136, no. 4 (2008): 377–86.

  17.  M. A. Joyce et al., “Births: Final Data for 2013,” National Vital Statistics Reports 64, no. 1 (2015): 1–68; A. D. Kulkarni et al., “Fertility Treatments and Multiple Births in the United States,” New England Journal of Medicine 369, no. 23 (2013): 2218–25.

  18.  Segal, Entwined Lives; P. Lichtenstein, P. O. Olaussen, and A. B. Källén, “Twin Births to Mothers Who Are Twins: A Registry-Based Study,” British Medical Journal 312, no. 7035 (1996): 879–81.

  19.  N. L. Segal, Indivisible by Two: Lives of Extraordinary Twins (Cambridge, MA: Harvard University Press, 2005); N. L. Segal and B. Marcheco-Teruel, “‘Street of Twins’: Multiple Births in Cuba” and “The Cuban Twin Registry: An Update,” Twin Research and Human Genetics 17, no. 4 (2014): 347–53.

  20.  It is not uncommon for family members’ impressions of twin type to conflict with results provided by DNA tests. Most often, identical twins are incorrectly classified as fraternal by their parents and other people who know them well and are very sensitive to subtle behavioral and/or physical differences between the two.

  21.  A. Fetters, “The Origins of Gabriel Garcia Marquez’s Magic Realism,” Atlantic Monthly, April 17, 2014; O. Kaplan, “García Márquez’ Magical Realism: It’s Real,” Political Violence @ a Glance, May 16, 2014, http://politicalviolenceataglance.org/2014/05/16/garcia-marquez-magical-realism-its-real/.

  22.  For the announcement of the branding campaign, see “Colombia, Magical Realism,” http://www.procolombia.co/en/news/colombia-magical-realism.

  23.  N. L. Segal, Born Together—Reared Apart: The Landmark Minnesota Twin Study (Cambridge, MA: Harvard University Press, 2012); P. A. Vernon et al., “A Behavioral Genetic Investigation of Humor Styles and Their Correlations with the Big-5 Personality Dimensions,” Personality and Individual Differences 44, no. 5 (2008): 1116–25; J. H. Stubbe et al., “Genetic Influences on Exercise Participation in 37,051 Twin Pairs from Seven Countries,” PloS ONE 1, no. 1 (2006): e22, https://doi.org/10.1371/journal.pone.0000022; D. P. Moloney, T. J. Bouchard, and N. L. Segal, “A Genetic and Environmental Analysis of the Vocational Interests of Monozygotic and Dizygotic Twins Reared Apart,” Journal of Vocational Behavior 39, no. 1 (1991): 76–109.

  24.  N. Eynon et al., “Genes and Elite Athletes: A Roadmap for Future Research,” Journal of Physiology 589, no. 13 (2011): 3063–70; N. L. Segal, “A Tale of Two Sisters,” Psychology Today, November–December 2015, 68–75, 88.

  25.  J. Shields, Monozygotic Twins: Brought Up Apart and Together (London: Oxford University Press, 1962); Segal, Born Together—Reared Apart.

  26.  M. F. MacDorman, T. J. Matthews, and E. Declercq, “Home Births in the United States, 1990–2009,” National Center for Health Statistics Data Brief No. 84 (2012), https://www.cdc.gov/nchs/products/databriefs/db84.htm.

  27.  J. M. Snowden et al., “Planned Out-of-Hospital Birth and Birth Outcomes,” New England Journal of Medicine 373, no. 27 (2015): 2642–53; American College of Obstetricians and Gynecologists, “Planned Home Birth,” Obstetrics and Gynecology 128, no. 2 (2016): 420–21.

  28.  MacDorman et al., “Home Births in the United States, 1990–2009.”

  29.  D. Boucher et al., “Staying Home to Give Birth: Why Women in the United States Choose Home Birth,” Journal of Midwifery & Women’s Health 54, no. 2 (2009): 119–26.

  30.  J. D. Davis et al., “Pregnancy Anxieties and Natural Recognition in Baby-Switching,” British Journal of Nursing 10, no. 11 (2001): 718–26.

  31.  Boucher et al., “Staying Home to Give Birth”; R. R. Rusting, “Baby Switching: An Underreported Problem That Needs to Be Recognized,” Journal of Healthcare Protection Management: Publication of the International Association for Hospital Security 17, no. 1 (2000): 89; “Identification Techniques for Preventing Infant Mix-Ups,” DNA Diagnostic Center, May 3, 2016, https://dnacenter.com/science-technology/articles/infant-mix-up-3.html.

  Chapter 6: Finding the Colombian Four

    1.  “Crossed Lives: Two Pairs of Twins Were Separated for 25 Years,” Caracol TV (Colombia, South America), October 26, 2014, http://www.noticiascaracol.com/septimo-dia/vidas-cruzadas-dos-parejas-de-gemelos-estuvieron-separadas-25-anos. Caracol Internacional is also available in nearly eighty countries across five continents, but the twins’ story was not widely distributed.

    2.  N. L. Segal, Someone Else’s Twin: The True Story of Babies Switched at Birth (Amherst, NY: Prometheus, 2011).

    3.  “Separate Twins Shall Face Legal Battle to be Compensated: Lawyer,” Caracol TV (Colombia, South America), October 26, 2014, http://www.noticiascaracol.com/septimo-dia/gemelos-separados-deberan-librar-batalla-juridica-para-ser-indemnizados-abogado.

    4.  N. L. Segal and F. A. Cortez, “Born in Korea—Adopted Apart: Behavioral Development of Monozygotic Twins Raised in the United States and France,” Per
sonality and Individual Differences 70 (November 2014): 97–104; P. Popenoe, “Twins Reared Apart,” Journal of Heredity 13, no. 3 (1922): 142–44; N. L. Segal, J. H. Stohs, and K. Evans, “Chinese Twin Children Reared Apart and Reunited: First Prospective Study of Co-Twin Reunions,” Adoption Quarterly 14, no. 1 (2011): 61–78.

    5.  Titus Maccius Plautus, Menaechemi (The Menaechmus Brothers), play, Archive of Performances of Greek and Roman Drama, http://www.apgrd.ox.ac.uk/productions/canonical-plays/menaechmi-the-menaechmus-brothers/500. The play was first performed in 1486 at the Palazzo del Corte (Ferrera, Emilia-Romana, Italy).

    6.  J. Weber-Lehman et al., “Finding the Needle in the Haystack: Differentiating ‘Identical’ Twins in Paternity Testing and Forensics by Ultra-Deep Next Generation Sequencing,” Forensic Sciences International 9 (March 2014): 42–46. This technique could also distinguish identical twin mothers from identical twin aunts, but the need to do this would be rare since only one is likely to be pregnant at a given time. A hypothetical exceptional case in which this could be valuable might involve an unwed identical twin mother who secretly relinquished a baby for adoption and contested her relationship to the child when the child tried to find her.

    7.  N. L. Segal, Twin Mythconceptions: False Beliefs, Fables, and Facts About Twins (San Diego: Elsevier, 2017).

    8.  N. L. Segal, Entwined Lives: Twins and What They Tell Us About Human Behavior (New York: Plume, 2000).

    9.  N. L. Segal and W. D. Marelich, “Social Closeness and Gift Giving by MZ and DZ Twin Parents Toward Nieces and Nephews: An Update,” Personality and Individual Differences 50 (2011): 101–5; D. M. Buss, Evolutionary Psychology: The New Science of the Mind, 4th ed. (Boston: Allyn & Bacon, 2012).

  10.  Segal, Born Together—Reared Apart.

  11.  Segal, Born Together—Reared Apart; K. S. Kendler, C. O. Gardner, and C. A. Prescott, “A Population-Based Twin Study of Self-Esteem and Gender,” Psychological Medicine 28, no. 6 (1998): 1403–9; T. J. Bouchard, Jr., et al., “Sources of Human Psychological Differences: The Minnesota Study of Twins Reared Apart,” Science 250, no. 4978 (1990): 223–28; M. McGue, J. W. Vaupel, N. Holm, and B. Harvald, “Longevity Is Moderately Heritable in a Sample of Danish Twins Born 1870–1880,” Journal of Gerontology 48, no. 6 (1993): B237–44.

  12.  Segal, Twin Mythconceptions.

  13.  Segal, Entwined Lives.

  14.  N. L. Segal with A. Altowaiji and C. K. Ihara, “The Birth of Octuplets: A Research Puzzle,” Twin Research and Human Genetics 12, no. 3 (2009): 328–31.

  15.  A. Tellegen et al., “Personality Similarity in Twins Reared Apart and Together,” Journal of Personality and Social Psychology 54, no. 6 (1988): 1031–39.

  16.  N. L. Segal, Indivisible by Two: Lives of Extraordinary Twins (Cambridge, MA: Harvard University Press, 2005); N. L. Segal, “Twinsters, the Movie: Reared Apart Twins in Real Time,” Twin Research and Human Genetics 19, no. 1 (2016): 80–85; Segal, Born Together—Reared Apart; N. L. Segal and M. Diamond, “Identical Reared Apart Twins Concordant for Transsexuality,” Journal of Experimental and Clinical Medicine 6, no. 2 (2014): 74.

  17.  American Psychiatric Association, The Diagnostic and Statistical Manual (DSM-5), 5th ed. (Arlington, VA: American Psychiatric Association, 2013); M. Diamond, “Transsexuality Among Twins: Identity Concordance, Transition, Rearing and Orientation,” International Journal of Transgenderism 14, no. 1 (2013): 24–38.

  18.  T. J. Polderman et al., “Meta-Analysis of the Heritability of Human Traits Based on Fifty Years of Twin Studies,” Nature Genetics 47, no. 7 (2015): 702–9; N. G. Waller and P. R. Shaver, “The Importance of Nongenetic Influences on Romantic Love Styles: A Twin-Family Study,” Psychological Science 5, no. 5 (1994): 268–74.

  19.  H. Fisher, A. Aron, and L. L. Brown, “Romantic Love: An fMRI Study of a Neural Mechanism for Mate Choice,” Journal of Comparative Neurology 493, no. 1 (2005): 58–62. The negotiator is intuitive and creative, and knows the thoughts and feelings of others; the director is devoted to personal and professional goals, with less interest in personal connections; the builder is people oriented, with loyalty to family, friends, and colleagues; and the explorer is energetic and fast paced, and may overlook the interests of others. H. Fisher, “What’s Your Love Type?” reprinted from O, the Oprah Magazine at CNN.com, November 16, 2007, http://www.cnn.com/2007/LIVING/personal/11/12/o.love.types/index.html?_s=PM:LIVING.

  20.  N G. Martin et al., “Transmission of Social Attitudes,” Proceedings of the National Academy of Sciences 83, no. 12 (1986): 4364–68; R. Plomin et al., Behavioral Genetics, 7th ed. (New York: Worth, 2016); V. Jocklin, M. McGue, and D. T. Lykken, “Personality and Divorce: A Genetic Analysis,” Journal of Personality and Social Psychology 71, no. 2 (1996): 288.

  21.  N. L. Segal, S. A. McGuire, and J. Hoven Stohs, “What Virtual Twins Reveal About General Intelligence and Other Behaviors,” Personality and Individual Differences 53 (2012): 405–10.

  22.  Segal, Entwined Lives; Segal, Stohs, and Evans, “Chinese Twin Children Reared Apart and Reunited.”

  23.  M. Herle et al., “Parental Reports of Infant and Child Eating Behaviors Are Not Affected by Their Beliefs About Their Twins’ Zygosity,” Behavior Genetics 46, no. 6 (2016): 763–71.

  24.  A. M. Burton and V. Bruce, “I Recognize Your Face but I Can’t Remember Your Name: A Simple Explanation?” British Journal of Psychology 83, no. 1 (1992): 45–60; M. Calabria et al., “The Missing Link Between Faces and Names: Evidence from Alzheimer’s Disease Patients,” Brain and Cognition 80, no. 2 (2012): 250–56.

  25.  “The Difference Between Translating and Interpreting,” Scientific Language, 2017, http://www.languagescientific.com/translation-services/multilingual-interpreting-services/interpreting-vs-translation-services.html.

  26.  Segal, Born Together—Reared Apart.

  27.  T. Spector, Identically Different: Why We Can Change Our Genes (New York: Overlook, 2012); A. H. Wong, I. I. Gottesman, and A. Petronis, “Phenotypic Differences in Genetically Identical Organisms: The Epigenetic Perspective,” Human Molecular Genetics 14, suppl. 1 (2005): R11–R18; A. Petronis et al., “Monozygotic Twins Exhibit Numerous Epigenetic Differences: Clues to Twin Discordance?” Schizophrenia Bulletin 29, no. 1 (2003): 169; D. Mastroeni et al., “Epigenetic Differences in Cortical Neurons from a Pair of Monozygotic Twins Discordant for Alzheimer’s Disease,” PloS ONE 4, no. 8 (2009): e6617. A new twin study from Denmark that used a novel statistical technique estimated higher identical twin similarity for schizophrenia, but it still did not reach 100 percent; see R. Hilker et al., “Heritability of Schizophrenia and Schizophrenia Spectrum Based on the Nationwide Danish Twin Register,” Biological Psychiatry (2017), DOI:10.1016/j.biopsych.2017.08.017.

  28.  G. Felsenfeld, “A Brief History of Epigenetics,” Cold Spring Harbor Perspectives in Biology 6, no. 1 (2014): a018200; Plomin et al., Behavioral Genetics.

  29.  L. Hou et al., “Environmental Chemical Exposures and Human Epigenetics,” International Journal of Epidemiology 41, no. 1 (2012): 79–105.

  30.  A number of molecular events can affect gene expression. A small chemical group, called a methyl group, can attach to a gene and silence it even though the gene is still present. Histone acetylation, the addition of a DNA-packaging acetyl group to a histone protein, also affects how genes get expressed, but both processes are reversible. Spector, Identically Different; “Research Kits: Histone Acetylation/Deacetylation,” Epigentek, 2017, https://www.epigentek.com/catalog/acetylation-deacetylation-c-75_24.html; D. Simmons, “Epigenetic Influences and Disease,” Nature Education 1, no. 1 (2008): 6.

  31.  Current technology makes it possible to sequence every DNA methylation mark in the human genome.

  32.  E. L. Dempster et al., “Disease-Associated Epigenetic Changes in Monozygotic Twins Discordant for Schizophrenia and Bipolar Disorder,” Human Molecular Genetics (2011): ddr41
6; G. C. Townsend et al., “Epigenetic Influences May Explain Dental Differences in Monozygotic Twin Pairs,” Australian Dental Journal 50, no. 2 (2005): 95–100; C. Selmi, “Primary Biliary Cirrhosis in Monozygotic and Dizygotic Twins: Genetics, Epigenetics, and Environment,” Gastroenterology 127, no. 2 (2004): 485–92.

  33.  H. Heyn, “DNA Methylation Profiling in Breast Cancer Discordant Identical Twins Identifies DOK7 as Novel Epigenetic Biomarker,” Carcinogenesis 34, no. 1 (2012): 102–8; Segal, Twin Mythconceptions.

  34.  S. Robertson, “What Is DNA Methylation?” Medical Life Sciences News, September 17, 2015, https://www.news-medical.net/life-sciences/What-is-DNA-Methylation.aspx; B. T. Heijmans et al., “Persistent Epigenetic Differences Associated with Prenatal Exposure to Famine in Humans,” Proceedings of the National Academy of Sciences 105, no. 44 (2008): 17046–49; M. Balter, “Can Epigenetics Explain Homosexuality Puzzle?” Science 350, no. 6257 (2015): 148.

  35.  D. Martino et al., “Longitudinal, Genome-Scale Analysis of DNA Methylation in Twins from Birth to 18 Months of Age Reveals Rapid Epigenetic Change in Early Life and Pair-Specific Effects of Discordance,” Genome Biology 14, no. 5 (2013): R42; Y. J. Loke et al., “The Peri/Postnatal Epigenetic Twins Study (PETS),” Twin Research and Human Genetics 16, no. 1 (2013): 13–20. Dr. Jeffrey Craig was at the Murdoch Children’s Research Institute, in Melbourne, at the time of our study.