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Triplets and Public Health

A reflection on identity, nature vs. nurture, research, and ethics.

Posted on July 30, 2018
Identical triplets pose for a photo and make the same expression

This past weekend, I saw a great movie. It was interesting, informative, entertaining, and disturbing all at once. The movie is called Three Identical Strangers. It is, in many ways, a meditation and reflection on identity, on nature vs. nurture, on research, and on ethics. It made me think about what we do in public health, how we think about causes, and what research and practice we support or do not support. But it also made me think about who I am, how I came to be this person and the role that heredity, environment, and simply chance played in my life. And it made me wonder what other paths would have been like. 

The movie tells the fascinating story of three identical triplets separated at birth and placed in very different families as a result of what it is subsequently revealed was an elaborate research study to finally resolve the controversy of the relative roles of nature vs. nurture. Researchers followed the triplets over time with careful observations of their behavior as they grew and until they were nearly in their twenties, when fortuitously, and somewhat miraculously, they found each other and the experiment had to end. 

When the triplets first emerged as a media sensation in the early 1980s emphasis was, as is often true in these cases, on how remarkably similar not only in physical appearance but in behaviors and in tastes (including “taste in women”!) the three young men appeared to be.  But as the movie and their lives evolve (and I won’t divulge much here, you must see the movie!) it becomes clear that their lives are actually remarkably different, and at the end based on seeing them and learning their life stories, you might not even suspect that they are identical triplets at all. 

A remarkable thing about the movie is how it illustrates through simple story telling the inextricable and interactive way in which genes, environment, and chance (yes simple chance, something we often neglect to pay attention to) mold our lives and ultimately shape who we become.  There are of course biologic correlates to all of this: the presence of gene by environment interactions, environmental influences on gene expression through epigenetic modulations, and the important role of random processes in biology. And these biological processes interact with social influences and broader environmental factors including the social systems that we live in. Not all is deterministic, of course. Chance and path dependency (how where you start shapes in part where you can go) play a major role in our lives and in who we become that we are sometimes reluctant to accept. 

But there is a disturbing underbelly to the film, and that largely has to do with the ethics of observing these triplets (and five additional sets of identical twins) fully knowing that they had identical siblings that they and their families were not aware of. The same researchers visited homes sometimes within 100 miles of each other to observe and compare the development of identical triplets or twins in different contexts. The movie also suggests that the triplets may have been purposefully placed by the adoption agency working in partnership with the researchers in homes previously identified as having very different parenting styles. Thus the parents were also unknowing subjects of the experiment. The findings of the study were never published, a fact the movie suggests makes things even worse. But should they have been given how the data were obtained? 

Interestingly, the film does not comment on the fact (discovered and shared with me later by a friend I saw the movie with) that the study was based at a renowned academic institution and funded by the National Institutes of Health. Study research assistants interviewed in the film highlight the unique opportunity this presented to conduct the “definitive” study of nature vs. nurture.  And if we are honest we must recognize that this is true. I think this tension between a sense that there is something profoundly, ethically wrong with what was done and yet our curiosity and desire to see what happens to the triplets reared apart (and how they are both remarkably similar and remarkably different at the same time) is what makes the movie fascinating but also profoundly troubling.

All this is food for thought in public health.  How do we acknowledge, study and act upon the complexity that drives our health?  What are the parameters for ethical research? What safeguards do we have in place and do they work? How do we operate ethically and yet ensure that we as a society learn what we need to learn to maximize everyone’s health in the future?  How do we recognize and communicate the complex ways in which our genes, our environments, and chance shape our health and transcend simplistic dichotomies?  

Some of these questions we can explore and address through our public health scholarship and our research. But fortunately in this, as in many other things, we have fiction and film to help us.

Ana V. Diez Roux, MD, PhD, MPH
Dean and Distinguished Professor, Epidemiology, Dornsife School of Public Health