The Genetic Lottery: Why DNA Matters for Social Equality

Paige Harden, Kathryn

Primary Category: Literature / Nonfiction

Genre: Treatise

Annotated by:
Trachtman, Howard
  • Date of entry: Mar-28-2022


The Graduate is a movie classic from what seems like a bygone era. It is accompanied by great music by Simon and Garfunkel and has one of the most famous one-word lines in cinema history. When Benjamin Braddock is wandering aimlessly around the pool at a graduation party thrown in his honor, a friend of his parents asks him what he plans to do with his post-collegiate life. Another family friend jumps in and volunteers, “Plastics.” There are many who will also give a one-word answer to any medical school graduate searching for a career – Genetics.

In this important new book,  Kathryn Harden provides staunch support for the key role of genetics in health, disease, and in human well-being. She provides a remarkably clear primer on genetics in accessible language. Harden begins with statistical issues like the normal distribution and Bayesian priors. In her capable intellectual hands, she uses analogies that effectively move the teaching agenda forward. With recipes as a framing image for genetics, she demonstrates the relationship between the coding material in the DNA nucleotide sequence and the actual building blocks, namely the proteins that do the heavy lifting inside cells. Concepts like genetic recombination, linkage disequilibrium, and monogenic versus polygenic disorders are introduced and make perfect sense. She then builds on this foundation to consider genome-wide association studies (GWAS) which represent the powerful tool that has been introduced to explore the relationship between genetic endowment and health. That is where things start getting complicated.

When people think of medical genetics, they usually have classical Mendelian disorders in mind. They are caused by mutations in a single gene that disrupts a protein pivotal to normal health. Examples are sickle cell disease, hemophilia A, or muscular dystrophy. However, many health problems like hypertension that are associated with significant global disease burden are polygenic. This means that they are caused by less dramatic mutations in a number of genes that in the aggregate lead to the disease.  Harden details how quantitative assessment of the contribution of these minor variations in a large array of discrete genes enables the formulation of polygenic risk scores (PRS) for these conditions. These measures provide estimates of susceptibility to developing other polygenic conditions like obesity, cardiovascular disease, and diabetes.

As a psychologist, Harden’s work focuses on the application of PRS to non-medical aspects of human behavior such as impulsivity, attentiveness, job satisfaction, and executive function. The waters remain relatively calm until Harden’s fellow psychologists venture into the realm of educational achievement and lifetime income status. Harden methodically reviews relevant studies that have been done with siblings, twins, adoptees, and family trios. She dissects them and highlights when investigators have misinterpreted their data. There is a steady drumbeat of data, almost too much at times. But the overall consensus that emerges is that PRS and other measures of heritability continue to show a genetic component for these psychosocial outcomes in large population studies. The challenge that Harden raises is how to incorporate this knowledge about genetics into a better understanding of these aspects of human behavior and if and how to address abnormal manifestations.

Questions remain concerning how genetics “causes” these changes and how to interpret the findings. What is determinative? Is it genetics i.e., nature, or is it all environment i.e., nurture? There are those, like Harden, who advocate for thoughtful analysis and utilization of all the GWAS data. She highlights the difference between use of PRS to assess outcomes within populations versus between populations. In sharp contrast, there are others who resist  the introduction of genetics into psychology. Pointing to the sordid history of eugenics and its degeneration into the creation of racial hierarchies, the opponents of the Harden’s work dismiss it as unscientific at best and destructive at worst. Harden makes a compelling case for the validity of the science and a spirited defense of the thoughtful use of genetics dismiss it as unscientific at best and morally repugnant at worst.

Harden provides a strong defense of the science and statistical methods and offers a spirited argument that without acknowledging the role of genetics in human achievement, society will be unable to thoughtfully address inequalities and restore balance. Her work touches on many other pressing issues including human autonomy, agency, freewill and the role of government intervention. She outlines a social agenda that acknowledges the importance of genetics as a contributing factor. But it incorporates a recognition that its distribution in the population is solely a matter of luck and does not serve as the basis for a hierarchy of human worth. I leave it to readers to judge for themselves the validity of her proposals, but her commitment to making this world a better place is not in question.


It is hard to exaggerate the timeliness of this book. Harden confronts a substantial issue that is being debated in the culture wars in which we are living. There are two key aspects that are highlighted in her work. First,  as with virtually every other topic on the political agenda, polarization is taken for granted. Thus, there are those for whom genetics represents the critical determinant of how our lives turn out. Our genetic endowment is an immutable factor and defines the capacity of social groups. The net result is to undermine any commitment to programs that are implemented to redress inequalities in outcomes. Standing across from them are those who downplay, even dismiss, genetics all together, and assert that unequal outcomes reflect intrinsic structural flaws in the organization of society that hinder equal access to resources and achievement. Those on the two sides of the line shout across the divide, cancel messages from their opponents, and are increasingly strident that their view is the right one, the only one.

Second, there is a skepticism about science itself. Harden’s work is demonized by her opponents on both sides. They accuse her of phony science, playing loose with the numbers, reading false meaning into her findings. It would be a fool’s errand to defend science as a pristine, mistake-free enterprise. It seems just as misguided to question Harden’s dedication to her work and her qualifications as an innovative research scientist.

There is a third aspect worth noting when reading this book and putting it into perspective. One of my favorite modern thinkers is Isaiah Berlin. He was famous as a defender of pluralism. As he saw things, the values that different people hold and the goals that they aspire to in life are often incommensurate with one another. There is no way to resolve the difference between two people with disparate notions of marriage, abortion, religion in the public square. For Berlin, the most viable solution is to configure society in a manner that at least tolerates multiple views and practices. Harden describes a comparable intellectual space where people assert a primacy of genetics or environment. Berlin would advocate for recognition and tolerance for each position. But I would push Berlin a bit more. Genetics vs environment represents an inability to see things in all their complexity. It is either/or rather than and/and. Everything is reduced to a unidimensional world. But is it that hard to imagine at least a two-dimensional world – genetics on the x-axis, environment on the y-axis? Instead of advocating for one of two positions and merely tolerating the other, it is essential to recognize the independent contribution of both. This would promote the understanding that each individual is a composite. To get a full description of a person mandates a full set of coordinates to locate them in nature vs nurture space. It would be a profound injustice to see him/her as anything less. Of course, we are all much more than 2-dimensional characters; but coordinating genetics and environment would be a good place to start the reconstruction work. Harden’s book is a courageous attempt to remind us of the complex, multidimensional task we face if we want to improve our lot individually and collectively.  


Princeton University Press

Place Published

Princeton, NJ



Page Count