Entwined Lives: Twins and What They Tell Us About Human Behavior [Paperback]

Nancy Segal (Author)

Book Description

Release date: April 1, 2000

Twins are nature's living laboratories. Through them we are able to uncover new information concerning the genetic and environmental factors affecting who we are. Studies using identical and fraternal twins hold the keys to understanding our intellectual abilities, personality traits, social attitudes, and behavior. In Entwined Lives, Dr. Nancy Segal brings together cutting-edge information with illustrative case histories of twins and their families. In addition to the fascinating stories of identical twins reared apart and reunited as adults, Dr. Segal provides insights into the unusual language patterns of twins, how twin studies affect legal decisions, the role of fertility treatments in twin and "twinlike" conceptions, and more. This groundbreaking book explores the ways in which twins enhance our knowledge of human behavioral and physical development, while shedding new light on the nature/nurture debate and on the burgeoning field of evolutionary psychology.

Editorial Reviews

From Publishers Weekly

Twin research has fueled bitter debates over the degree of genetic influence on intelligence, disease, mental disorders, special abilities and other traits. Almost encyclopedic in scope, this elegantly written study cogently distills and makes available to the general reader a wealth of research from the fields of behavioral genetics, evolutionary psychology and social science. A professor of developmental psychology and director of the Twins Study Center at California State, Fullerton, Segal contends that studies of twins, raised together or apart, demonstrate that genetic influence affects virtually every human characteristic, including IQ, personality, longevity, sociability, job preference and satisfaction, mathematical skills and athletic prowess. Parents, surprisingly, tend to be highly inaccurate judges of whether their offspring are identical or fraternal twins. Segal endorses testing during pregnancy or routine DNA analysis of newborns, arguing that knowledge of twin type affects parents' and educators' management of twins' behavior. A twin herself, Segal includes helpful chapters on the bonds twins develop, on how to cope with the loss of a twin and on conjoined twins, among other subjects. She also guides readers through new fertility treatments that may increase the odds of conceiving multiples. This survey will capture the imagination of anyone curious about twins or human behavioral development. Photos. Agent, Angela Rinaldi.
Copyright 1999 Reed Business Information, Inc. --This text refers to an out of print or unavailable edition of this title.

From Library Journal

In the most significant survey of twin research to date, Segal (director of the Twins Study Ctr. at California State Univ., Fullerton, and a fraternal twin herself) illustrates that by using twins as "living laboratories" we can sort out which aspects of twins' lives are influenced by genetic inheritance, and, in turn, we can begin to "lay bare the basis of human behavior." Drawing on all sorts of twin studies, Segal describes twin types and elaborates on findings regarding the development of personality and intelligence. She also looks closely at twin relationships (including conjoined twins) to understand grief, competition, bonding, cooperation, and more. Most refreshing are Segal's frank discussion of the complications inherent in the research and her many proposals for further research. Though her prose is dense, it holds plenty for anyone interested in twins or in fine questions of human development and evolutionary psychology. This is an excellent supplement to Lawrence Wright's more popularly written Twins: And What They Tell Us About Who We Are (Wiley, 1997). Recommended for academic and public libraries.ARebecca Miller, "Library Journal"
Copyright 1999 Reed Business Information, Inc. --This text refers to an out of print or unavailable edition of this title.

See all Editorial Reviews

Product Details

• Paperback: 416 pages
• Publisher: Plume; 1 edition (April 1, 2000)
• Language: English
• ISBN-10: 0452280575
• ISBN-13: 978-0452280571
• Product Dimensions: 6 x 0.9 x 9 inches
• Shipping Weight: 14.9 ounces
• Average Customer Review: 4.3 out of 5 stars  See all reviews (20 customer reviews)
• Amazon Best Sellers Rank: #991,234 in Books (See Top 100 in Books)

More About the Author

Nancy L. Segal, Ph.D. (CA), is a professor in the Department of Psychology at California State University, Fullerton, and the director of the Twin Studies Center, which she founded in 1991. She is the author of Indivisible by Two: Lives of Extraordinary Twins and Entwined Lives: Twins and What They Tell Us about Human Behavior, and the senior editor of Uniting Psychology and Biology: Integrative Perspectives on Human Development. She is also an associate editor of Twin Research and Human Genetics, the official journal of the International Society for Twin Studies. Dr. Segal's media appearances include Today, Good Morning America, 20/20, the Oprah Winfrey Show, the Martha Stewart Show, Discovery Health, and the Diane Rehm Show on NPR.

Author photo by Michael Keel

Most Helpful Customer Reviews

30 of 31 people found the following review helpful

3.0 out of 5 stars At times interesting but more often long-wided and anecdotal October 10, 2003

By MS

Format:Paperback

In Entwined Lives, researcher Nancy Segal draws upon hundreds of case studies to explore the physical development of twins, and to tackle the thorny nature-versus-nurture question. Segal is competent and often interesting when she sticks to the former; her forays into the latter, on the other hand, are long-winded and anecdotal, and clearly highlight her shaky grasp of statistical methods, not to mention the benefits of editing.

Among the more interesting ideas raised in the book is a detailed description of the different ways in which twins develop in utero from conception onward. I also found intriguing a description of a third type of twin, one in which both siblings share their mother's, though not their father's genes. This second topic, though, is barely developed, and there is little mention of how twins of this type are identified. This is typical for the book - interesting ideas are raised and then promptly abandoned, leaving the reader with little understanding or context.

At the same time, Segal does not hesitate to make broad generalizations about genetics and socialization from small collections of anecdotes. Much of the book is devoted to demonstrating the influence of genetics upon intelligence, behaviour, and athletic ability. A chapter on twins separated at birth is well-written and its methods well-described, but it's the exception. On the whole, this section is filled with dozens of case studies and stories from which Segal draws a multitude of conclusions, some better founded than others. She has ample data to support her uncontroversial claim that genetics play a large role in determining intelligence and similarities in abilities, and belabours this obvious point for several chapters during much of the book.... (Do we really need several paragraphs explaining that height and weight play a role in determining athletic ability?)

But she is just as prepared to base her theories on a story here, a fact there: one identical pair's preference for very rare meat, for instance, prompts Segal to hypothesize that not only do identical twins share preferences, but that the things they enjoy are likely to lie outside the mainstream. She also ponders at length the significance of one athletic twin claiming an Olympic gold while his cotwin ended up with the silver. After a paragraph of grade-school-level speculation, she raises the (most likely) possibility that the medal discrepancy doesn't mean anything. This book is filled with these sorts of useless, irrelevant tangents (the most bizarre involving a mention of the wholly theoretical "twins paradox" from special relativity in a section on a pair of identical astronauts) that go absolutely nowhere, and that should have been edited out of the first draft of the book. She devotes virtually no space whatsoever to explaining which of her data are statistically meaningful, but rambles at length about very minor aspects of her methodology, such as choosing the most suitable acronym to denote biologically unrelated same-age siblings.

The stories in Entwined Lives make for entertaining, if light, reading, and would have been more enjoyable if Segal didn't keep interrupting them with unsupported generalizations, or with the dozens of "see? Genetics ARE important" assertions that appear over and over again. And the scientific data would have been more useful had it been better, or more rigorously developed. As a book about human behaviour, which it claims to be, it is too long, and explains too little. Read more ›

13 of 13 people found the following review helpful

5.0 out of 5 stars Superbly written and brimming with twin/human revelations April 21, 1999

By A Customer

Format:Hardcover

Dr. Nancy Segal has further drawn back the curtain shrouding the mysteries of human behavior with this enduring observation. I found the book reveals an enormous amount about ourselves through the study of twins. Dr. Segal is a gifted researcher with an exquisite writing style. She takes elaborate research topics and explains them in ways that we all can understand. Page after page, the book reveals new information about how we humans develop through nature and nurture, the end result being that our genetic design has more to do with who we are than we every imagined.

The book gives us significant insight far beyond the surface interest most have in twins. I found the book also very entertaining with its numerous ancedotes and real-life stories about twins. Being a twin myself, the book helped me gain new perspective about my twinship and eliminate many eroneous perceptions/myths about twins.

16 of 17 people found the following review helpful

5.0 out of 5 stars Fascinating November 3, 2001

By Erika Mitchell TOP 500 REVIEWERVINE™ VOICE

Format:Hardcover

This book provides an encyclopedic overview of research about twins. When I first opened the book, my initial reaction was "ouch", because of the densely packed font. The reason for the denseness is that Segal has so many topics to cover and so much information to share with us that the letters had to be squeezed to get it all into one volume. But not to fear - - there are pictures sprinkled throughout the text.

Segal, a twin herself, has been researching twins for over 20 years, since her undergraduate studies. This book sums up much of that research in a format that is approachable by general audiences (and includes extensive endnotes to help interested readers find the studies that are cited). The many topics in her book include: identical twins, fraternal twins, twins reared apart, children adopted together, conjoined twins, non-human twins, friendship between twins, loss of a twin, famous twins, mental skills, athletic skills, and behavioral traits.

One of the most interesting results of Segal's and others' twin research is the strong influence that genes have on intelligence, behavioral traits, and athletic ability. Segal reports that identical twins, reared together or apart, are remarkably similar in these areas, and become more so as they get older. The similarity is weaker with fraternal twins, siblings, and cousins, and hardly found at all between unrelated same-aged children raised together. Certain health factors on the other hand, seem to be more dependent on environmental factors and life choices than on genetics, such as aging of the skin and heart disease. Many of Segal's results come from research on identical twins reared apart, in whom strong similarities point to genetic programming since the environments in which they were raised were different.... The logical opposite of identical twins reared apart is unrelated same-aged children reared together, in whom any similarities would suggest environmental influences. Segal has a short chapter on such siblings, but this area could really use more research to complement what has been done with twins reared apart.

This book is absolutely fascinating for what it says, not only about twins and other multiples, about the siblings and parents of twins, about adopted children, but also about humans in general. Read more ›

10 of 10 people found the following review helpful

5.0 out of 5 stars Fascinating book about twins, family ties, genetic influence April 28, 1999

By A Customer

Format:Hardcover

I bought this book because I am an identical twin and I was curious about recent research on twins. Segal is certainly the expert here. However she goes beyond just the facts of the studies and ties in lots of interesting information and theories about how genetics influences our behavior and our attachments to the people in our family. Her theories on the reasons for the closeness of a mother to her children were very interesting to me.

This book has much to offer to different people - it discusses general interest topics like why we behave the way we do and end up a certain way. It should also be a "must read" for any identical twin or parent of a twin. Segal does an extraordinary job of describing the special relationship that exists between identical twins.