Abstract
Few topics in psychology and popular culture generate so much controversy, are so provocative, and are riddled with more misunderstandings than research on behavioral genetics. One misplaced criticism is that of twins research being based on anecdotes. Indeed, Dr. Segal previously recounted tales of twins in her last book, Indivisible by Two (Segal, 2005); a book I reviewed for this very journal (Jonason, 2007). However, her new book is a tour-de-force of the methods, science, and results of the actual research conducted by her and others involved in the Minnesota Twins Reared Apart Study (MISTRA). She recounts some of the landmark results of the studies, reporting details previously not reported in a single source. She covers topics such as sexual orientation, intelligence, dentition, and anthropometrics. As such, this book seems well placed for an academic audience. It provides the detail one might need to start a research program of their own in behavioral genetics. In contrast to her other books, it is really written for “the scientist” more than those simply interested in the coincidences, cute stories, and touching reunions of twins. In fact, her last chapter contains details about what reviewers of MISTRA grants have had to say; something to which anyone who has submitted a grant or manuscript can relate.
There is a subtler theme that only becomes evident in the last chapter. The MISTRA project has generated considerable debate, disturbed the apple cart for many researchers who adopt the Standard Social Science Model, and has repeatedly been mischaracterized in the media and by other researchers. Her book attempts to be the final word about some of the criticisms. For instance, one criticism that seems to follow the MISTRA is the use of monies from the Pioneer Fund. The Pioneer Fund has a questionable history and agenda. Dr. Segal does away with this and other criticisms by both recounting stories and conversations with her collaborators on the MISTRA, but also by providing a clear description of why many of the misunderstandings are based on critics' misguided or misinformed understanding of the research. Indeed, some of the criticisms of the MISTRA are completely off base, and she does away with them in one fell swoop.
The well-informed evolutionary psychologist will enjoy much of this book. The book details the role behavioral genetics and the MISTRA researchers (e.g., Bouchard) have played in chipping away at the entrenched remnants of radical behaviorism, the Standard Social Science Model, and the blank slate fallacy. Notably, drawing attention to even modest heritability effects on personality, intelligence, and political attitudes (just to name a few) is extremely problematic for these researchers. How can their models account for effects that are not learned? Of course, they cannot, so what they must do is criticize the methods (e.g., small sample sizes) or analyses (e.g., intraclass correlations), revealing that they hold on to their position in a dogmatic fashion. Dr. Segal's book addresses all of these issues and more. Now, I have little hope that critics of behavioral genetics will read her book given the confirmation bias, but this book will surely equip those of us who are amenable to behavioral genetics findings to combat such criticisms. Like the criticisms against evolution, the criticisms against the MISTRA studies are standard and specious and we should all learn how to demonstrate their falsity.
Laypeople may object to the MISTRA's findings for one underlying reason: The results appear to suggest that there is nothing they can do to make their child better in X domain. The results seem to fly in the face of their sense of self-importance in rearing their children. This is a naïve misunderstanding of the intricacies of raising a baby into an adult. For instance, it ignores the preeminence of genes in determining intelligence. Take, for instance, severe mental handicaps. No amount of parental love and care can make a son suffering from Down's Syndrome smarter or to not have that syndrome anymore. Indeed, such an attitude has the laughable corollary that if male chimpanzees were hugged and kissed more they would not hunt Colobine monkeys and they would stick to eating figs. This is “hippie psychology” at its finest. In addition, such findings disturb ideological guidelines like in Christian Science whereby parental prayer is sufficient to alter a child's “nature.”
There is something to be said for the value the MISTRA studies provide as guidance for parents. The studies reveal that “parents should pay close attention to each child's unique character traits and nurture each child's individual interests” (Segal, 2012, p. 102). This means that in contrast to the misperception that behavioral genetics undermines the role of parents, it merely qualifies the parental role and offers a new model for parenting. It suggests that “parental fairness seems more likely to come from treating children differently in accordance with their individual behaviors than treating them alike” (Segal, 2012, p. 102). When one thinks about it, this is a better parental model. It moves one from thinking about tactics in parenting (e.g., taking son to soccer games) to strategies in parenting (e.g., facilitating daughters interest in science). That strategy is: determine what each child is good at and nurture that. In fact, although Dr. Segal does not mention this in her book, this might even point to ways by which we can improve the education systems around the world.
In sum, when I started reading this book my first thought was, “do we really need another book on this topic?” Now that I have read it, my answer is an unequivocal “yes.” The book provides an important resource to other academics and any serious scholars who want to understand what makes us who we are, and how researchers go about working that out.