A 2022 Choice Reviews Outstanding Academic Title
Takes the first in-depth look at the New York City adoption agency that separated twins and triplets in the 1960s, and the controversial and disturbing study that tracked the children’s development while never telling their adoptive parents that they were raising a “singleton twin.”
In the early 1960s, the head of a prominent New York City Child Development Center and a psychiatrist from Columbia University launched a study designed to track the development of twins and triplets given up for adoption and raised by different families. The controversial and disturbing catch? None of the adoptive parents had been told that they were raising a twin—the study’s investigators insisted that the separation be kept secret. Here, Nancy Segal reveals the inside stories of the agency that separated the twins, and the collaborating psychiatrists who, along with their cadre of colleagues, observed the twins until they turned twelve. This study, far outside the mainstream of scientific twin research, was not widely known to scholars or the general public until it caught the attention of documentary filmmakers whose recent films, Three Identical Strangers and The Twinning Reaction, left viewers shocked, angered, saddened and wanting to know more.
Interviews with colleagues, friends and family members of the agency’s psychiatric consultant and the study’s principal investigator, as well as a former agency administrator, research assistants, journalists, ethicists, attorneys, and—most importantly--the twins and their families who were unwitting participants in this controversial study, are riveting. Through records, letters and other documents, Segal further discloses the investigators’ attempts to engage other agencies in separating twins, their efforts to avoid media exposure, their worries over informed consent issues in the 1970s and the steps taken toward avoiding lawsuits while hoping to enjoy the fruits of publication. Segal's spellbinding stories of the twins’ separation, loss and reunion offers readers the behind-the-scenes details that, until now, have been lost to the archives of history.
Nancy L. Segal, PhD, is Professor of Psychology at California State University, Fullerton and Director of the Twin Studies Center. She has authored over 250 scientific articles and six books on twins and twin development—a recent survey placed her among the top 2% of well-cited scientists worldwide. Segal’s 2012 book, Born Together-Reared Apart: The Landmark Minnesota Twin Study, won the 2013 William James Book Award from the American Psychological Association. Her other books include Twin Mythconceptions: False Beliefs, Fables and Facts About Twins (2017), Someone Else’s Twin: The True Story of Babies Switched at Birth (2011), Indivisible by Two: Lives of Extraordinary Twins (2007) and Entwined Lives: Twins and What They Tell Us About Human Behavior (2000). Her most recent book, Accidental Brothers (2018), follows the incredible life histories of two sets of identical male twins in Colombia who were inadvertently switched at birth. She has appeared on the Today Show,CBS This Morning, Good Morning America and the Oprah Winfrey Show, and been featured in the New York Times, Wall StreetJournal and Atlantic Monthly.Segal has also served as a consultant and expert witness for the media, the law and the arts. Born in Boston and raised in New York City, she lives in southern California.
I. d how the situation mya be appropriately addressed.gregius s findings from visits with two sets of accidentII. I. Twin Studies: Illustrious and Ignoble
II. Separated by Design: Policy and People
III. Inside the Twin Study: How Did It Work?
IV. Familiar Strangers: Twin Brothers with Twin Sisters
V. Kathy and Betsy: “The Biggest Thing in My Life”
VI. Media Inquiry: Sixty Minutes
VII. Anne and Susan: Dancing Solo
VIII. Melanie and Ellen: Identical, but Not the Same
IX. Doug & Howard: Parallel Lives
X. Identical Triplets: Three Versions of the Same Song
XI. Sharon: Twinless Again
XII. In Search of the Findings: Unpublished or Unavailable?
XIII. The Book That Never Was: Yale University Press
XIV. Justin: Not Just a Doppelgänger?
XV. Paula and Elyse: Artists From Afar
XVI. Paula and Marjorie: Opportunities Lost
XVII. Michele and Allison: Fraternal, Almost Identical
XVIII. Letters of Protest: Oscars and Emmys
XIX. Professional Standards: Codes of Conduct, Legalities and Moralities
XX. Controversies: Over or Unfinished?
About the Author
This outstanding volume describes the author's persistent efforts to overcome the roadblocks encountered at every step as she tried to uncover the details of the study. Segal adopts a sympathetic tone in describing the impact of the research on adopted twins who discover each other. At the same time, she pulls no punches in identifying the ethical issues that the researchers should have considered. This masterful book will appeal to readers interested in developmental psychology, research ethics, research methodology, personality, behavior genetics, and theories of psychology. Highly recommended. Lower- and upper-division undergraduates. Graduate students and faculty. General readers.
In the 1930s a famous radical behaviorist had conjectured that given a dozen healthy infants he could take anyone at random and transform in any type of specialist, doctor, lawyer, and even beggar and thief, regardless of children’s tendencies or abilities. This was a thought experiment, which has never been carried out in practice, and the reasons are obvious. It would be antithetical and unimaginable. Generations of psychology students take knowledge and debate this thought experiment during their undergraduate courses. This was a thought experiment, which has never been carried out in practice, and the reasons are obvious. Now we find that unlike the radical behaviorist, who was strictly ethical, a group of psychoanalysts and psychiatrists conducted the experiment with twins, without parents’ knowledge, in the 1960s. Professor Nancy Segal, Director of the Twin Studies Center at California State University, Fullerton, wrote the book Deliberately Divided about this controversial study of twins and triplets adopted apart and observed until they turned twelve. Segal opened the archives of history and analyzed the information in-depth on the basis of her decades of experience working with twins. As a professor of psychology, I consider this an important book for the formation of students and I recommend its translation into Portuguese.
The documentary Three Identical Strangers captivated viewers with the story of identical triplets who were separated at birth, studied by psychiatrists, and kept unaware of one another’s existence. Deliberately Divided is the inside story of the history and science behind this disturbing event, told by a leading researcher and a gifted expositor.
Before reading Deliberately Divided it never occurred to me that a book on the study of twins could be a gripping drama. Yet here, Nancy Segal, herself a professor of psychology (and a twin), writes so movingly about an unfortunate twin study that deliberately left many twins to grow up apart. Was this disruption of human lives worth the cost just to learn something about human nature? I was on the edge of my seat waiting to find out what happened when the long-separated twins found each other later in life. This is one of the most educational and entertaining books on psychology I’ve ever read.
This is surely the last word on studies of twins raised apart, the most profound experiment nature has to offer on the relative contributions of genes and the environment to the makeup of the human personality. Nancy Segal has given us a career’s-worth of insight into the twin experience.
A rich, moving, and comprehensive account of a human drama every living person can identify with. Being both a twin and a twin researcher with deep experience in the domain under discussion, Dr. Segal brings a unique perspective to bear on the moral and ethical issues this controversial study raises. She touches every base with clarity, compassion, intelligence and common sense.
Deliberately Divided is a superb read! Written by Nancy L. Segal, a top international expert on twin research, the book conveys the amazing stories of the twins, their families, and the investigators behind a controversial study of intentionally separated twins and triplets who were secretly studied in the 1960s–70s. Deliberately Divided is a must-read for anyone concerned with human studies, research ethics, and the welfare of children. You will be riveted from start to finish as I was.
Segal’s expertise on twins raised apart, primarily from her training and work on the Minnesota Study of Twins Reared Apart, makes her the ideal researcher to write this current book.... An incredible amount of detective work was needed to put together the very complicated minutiae of this story of how twins and triplets were separated and how they were studied. Segal does a strong job of describing her entire data collection process.... Researchers and others who became aware of this series of events from recent films, such as Three Identical Strangers, will find the details provided in Segal’s book to be illuminating....
Typical of all of her books, Deliberately Divided couples Segal’s research skills, worthy of those of a Pulitzer-class investigative journalist, with rigorous scientific interpretations and her own perceptive ideas and insights regarding what may or may not have actually happened and why. Her combination of fascinating accounts about the twins, their families, and the protagonists at LWS-CDC and her in-depth treatment of the scientific, legal, and ethical issues surrounding the controversial study will make the book appealing to readers from all walks of life. The whole book is the epitome of sound scholarship and makes fascinating reading
Deliberately Divided [is] the most thorough account of this scandalous episode to date. Segal is an eminent behavioral geneticist who has spent her career wrestling with issues raised by the study of twins, and her new book is by turns moving, infuriating, and enraging. Everybody who thinks about human nature and scientific research should read it…. One of the strengths of Segal’s account is its dispassionate and thorough analysis of the ethical thorns and tangles of the LWS-CDC study. She clearly finds the study abhorrent…[b]ut she does not allow her outrage to overwhelm her prose or cloud her judgment.... Deliberately Divided is a well-researched and careful book about a shameful episode in the history of US science. Segal is scrupulously fair and has refused to fill her book with caricatured villains and blemishless heroes. Drs. Neubauer and Bernard are presented as three-dimensional humans who are likable, intelligent, and even admirable, but also severely flawed. It is to Segal’s credit that she allows the reader to see this while also unequivocally denouncing all involved for their behavior.
This book contains a subtly nuanced, and balanced discussion of these issues and a sympathetic study of the personalities and attitudes involved, and the scientific and moral climate at the time which led to this twin study. It can serve a lesson to researchers of how the allure of making significant findings can blind them to the ethics of what they are doing. There are few scholars more eminent in the field of twin studies than Nancy Segal with at least eight books and over 250 publications to her name. It is therefore unsurprising that she manages to draw together with ease, economy, and clarity the findings on twins relevant to this, her latest, book. When she was asked to write about this controversial area, she had misgivings, but in the end she agreed. This highly readable book is the result, in which she deftly steers a course between the science of twins, the ethics of research, the interests and feelings of those twins studied and the histories and personalities of the people involved….This book is full of rich detail, clearly described and placed in context… Segal’s grasp of detail and ability to order it clearly is most impressive.
[T]o call this book detailed is like calling Mount Everest an interesting pile of rocks – it just doesn’t quite capture its full nature and grandeur. The details, however, do not overpower what is a highly readable and informative book. Segal truly captures the totality of the stories of the individuals impacted by these events and a reader will experience a wide range of emotions throughout the book’s chapters…. An incredible story requires an incredible storyteller, and Segal completely delivers. She is uniquely suited to tell this story an informed manner as she can speak to the overall science and methodology of twin studies. Perhaps more importantly, she also possesses the experience and care to properly elucidate and contextualize the multitude of stories surrounding the LWS-CDC study – especially those of the twins and their families. This book is a must-read not only for those interested in the etiologies of the human condition, but also for any researcher or student of psychology and human development.
Nancy Segal is an extraordinary expert who has been devoted to twin studies for most of her professional life. Thanks to this experience, her presentation encompasses much more than a single research project. She knows the detailed stories of hundreds of twins from the unique cohorts of twins who were reared apart or switched-at-birth (Segal, 2012). Her talent as a writer has presented readers with several books on these topics, and perhaps no one could better tell the story of the LWS-CDC study, which has shocked the viewers of the TV shows and films about the study. It is quite easy to take the side of the creator of the hottest news. But truth requires sensitivity, expertise in the field of the research object, and Socrates’ ability to catch and explain contradictions and change optics, to reveal the motivation of all participants in the described. In this book, Segal managed to accomplish those feats.
Segal’s ability to dramatically describe stories of twin separation, loss and reunion offers the reader an unforgettable experience of coming to know the twins and triplets involved in the study. The book is impressively researched and meticulously told.
Deliberately Divided uses its platform to demonstrate and restore respect for the many individuals (especially, but not only the twins and triplets) impacted by the study. It calls contemporary researchers to reflect on how such events could have transpired-and how we must hold ourselves and our colleagues to higher ethical standards to ensure that such disrespect for persons does not reoccur.
8/2/21, Keep Talking podcast: Nancy Segal talks about her research on identical twins and her new book.
9/26/21, Quillette: Nancy Segal wrote an article about her experiences working on the book.
11/5/21, Orange County Register: Local professor Nancy Segal is interviewed in a feature article about the book.
11/9/21, The Michael Shermer Show on Skeptic: Dr. Michael Shermer interviewed Nancy about the book.
11/10/21, AirTalk with Larry Mantle on KPCC-FM (Los Angeles): Nancy was interviewed about the book.
11/10/21, Get Real Health Podcast: Dr. Chana Davis interviewed Nancy about how twins are studied and previewed the book.
11/13/21, Quillette Podcast: Nancy Segal discussed the book and her career spent studying twins.
11/28/21, Psychology Today: Nancy Segal wrote an article highlighting new books about twins, including her own.
12/8/21, Talk with Francesca: Nancy Segal was interviewed about the book on this podcast episode.
12/11/21, New York Post: The book and author are featured in this article.
12/15/21, Twins Magazine: Nancy Segal did a Q&A about the book.
1/6/22, Steph’s Packed Lunch: Nancy did a live interview about the book with host Steph McGovern on this popular UK television show.
1/9/22, Twiniversity: Nancy Segal’s book was featured in this article, and she was interviewed about twin misconceptions in this podcast episode.
1/20/22, Twintopia podcast: Nancy Segal was interviewed about the book and her twin research.
3/17/22, Daily Titan: A feature has posted on Nancy Segal’s twin research and her latest book.
3/31/22, Sibling Revelry with Kate Hudson and Oliver Hudson: Nancy Segal joined the sibling actors to talk about the book and all things twins.
4/27/22, New Books Network: Nancy Segal was interviewed about the book in this episode.
5/6/22, BBC News: Nancy Segal was interviewed for this article about lost twins and how to find them.
5/20/22, Twin Research and Human Genetics: The author posted an OA journal article related to the book.
6/3/22, Teen Scientist on WDIY: Nancy Segal discussed the book and her groundbreaking work.
8/1/22, BBC World News: Nancy Segal was featured in this documentary “Split at Birth: Twins Divided” and book is shown.