Looking beyond what survived to understand the complete picture
Introduction
When we study history, we naturally focus on what remains: the buildings still standing, the books preserved through centuries, the businesses that thrived, the medical treatments that worked. This tendency creates what statisticians call “survival bias” – a logical error where we concentrate on people or things that made it past some selection process while overlooking those that did not, leading to false conclusions and distorted perspectives.
While the bullet-hole-riddled WWII aircraft example is perhaps the most famous illustration of survival bias, history offers us countless other illuminating cases that reveal how this cognitive error shapes our understanding of the past and influences our decisions today.
The Healthy Worker Effect: Industrial Revolution’s Hidden Truth
During the Industrial Revolution and early 20th century, medical researchers made a puzzling discovery: factory workers, despite laboring in what we now know were often hazardous conditions, frequently appeared healthier in statistical studies than the general population.
This counterintuitive finding, known as “the healthy worker effect,” represented a classic case of survival bias. Only individuals with robust constitutions could endure the punishing physical demands of factory work. Those who became ill simply disappeared from the workforce—and consequently from the studies—creating a false impression about working conditions.
The healthiest workers remained visible in the data, while those whose health deteriorated became invisible. This statistical illusion delayed necessary workplace safety reforms and obscured the true human cost of industrialization for decades. Only when researchers began tracking workers longitudinally and accounting for those who left the workforce did the actual health impacts become apparent.
The Deceptive Durability of Ancient Architecture
We marvel at structures like the Roman Pantheon, with its magnificent unreinforced concrete dome that has stood for nearly two millennia, while modern concrete often deteriorates within decades. This observation has led many to conclude that ancient Roman engineers possessed superior construction knowledge that was somehow “lost” to history.
However, this represents a classic survival bias. What we see today are only the most exceptional examples of Roman architecture—the statistical outliers that survived earthquakes, wars, and the relentless erosion of time. For every Pantheon or Colosseum that remains, thousands of ordinary Roman structures collapsed long ago and were forgotten.
Recent archaeological work has revealed that Roman concrete wasn’t universally superior—many structures failed quickly, but these failures don’t remain for us to observe. The structures that survived often did so because they were built in geologically stable areas, constructed with extraordinary resources by the empire’s finest engineers, or continuously maintained and restored throughout history.
When we consider only the survivors, we mischaracterize the typical Roman building experience and create false narratives about “lost knowledge,” when in fact modern materials science has produced far more reliable and consistently durable building materials.
Medieval Knowledge: The Monastery Filter
Our understanding of medieval thought and culture is profoundly shaped by survival bias. The vast majority of surviving manuscripts from the Middle Ages come from monasteries and religious institutions—texts deemed worthy of careful preservation and painstaking reproduction by scribes.
This creates a fundamentally skewed historical record. Religious perspectives, classical works approved by the Church, and writings by social elites are dramatically overrepresented, while secular literature, folk traditions, dissenting religious views, and the perspectives of ordinary people were far less likely to be preserved.
Historians estimate that less than 1% of all medieval manuscripts survived to the modern era. This tiny fraction profoundly shapes our perception of medieval society, making it appear more uniformly religious and intellectually constrained than it likely was. Recent archaeological finds, like the Novgorod birch bark documents in Russia—everyday letters written by ordinary citizens—suggest a much more diverse intellectual landscape than surviving formal manuscripts indicate.
The “Spanish” Flu Misnomer
The deadly influenza pandemic of 1918-1919 became known as the “Spanish Flu” not because it originated in Spain or because Spain suffered more severely, but because of a quirk of information survival. As a neutral country during World War I, Spain had no wartime press censorship, unlike most other affected nations.
While countries like the United States, Britain, France, and Germany suppressed news about the outbreak to maintain wartime morale, Spanish newspapers reported freely on the disease, including the illness of their king, Alfonso XIII. This created the false impression that Spain was uniquely affected when the pandemic was truly global in scope.
Modern research suggests the virus likely originated in the United States or China, but the survival bias in public information—with Spanish reports “surviving” censorship while others didn’t—created a historical distortion that persists in the pandemic’s name over a century later.
Literary Canons: The Survival of the “Greatest”
When we study literature from past centuries, we focus on what literary scholar Franco Moretti calls “the canonical 1%”—the tiny fraction of published works that have been preserved, anthologized, and continuously read. This creates the illusion that past eras produced mostly masterpieces, unlike our own time with its mix of great, good, and forgettable works.
In reality, Sturgeon’s Law—the principle that “90% of everything is crud”—applied just as much to Victorian novels or Renaissance plays as to modern literature. For every Shakespeare, there were dozens of forgotten playwrights; for every Jane Austen, hundreds of forgotten novelists whose works didn’t survive the ruthless filter of time.
This survival bias distorts our perception of literary history and creates unrealistic standards for contemporary writers. It also means our understanding of past literary cultures is based almost entirely on exceptional outliers rather than typical works.
Medical Treatments: History’s Selective Memory
Medical history provides particularly consequential examples of survival bias. Before the advent of rigorous clinical trials, doctors primarily recorded and passed down treatments that seemed to work, creating a body of medical literature rife with survival bias.
When patients recovered after a particular treatment, the treatment received credit—regardless of whether recovery might have happened anyway. Treatments that failed were less likely to be documented or, if documented, less likely to be repeatedly cited in medical texts.
This created a medical canon filled with ineffective or even harmful treatments that persisted for centuries. Bloodletting, for instance, remained a standard medical practice for over 2,000 years despite causing more harm than good in most cases. It survived because doctors noticed and remembered the subset of patients who improved after bloodletting (often despite the treatment, not because of it), while minimizing or forgetting the many who deteriorated.
Only with the development of controlled trials in the 20th century, explicitly designed to counter survival bias by tracking all outcomes, did medicine begin to systematically separate truly effective treatments from those that merely appeared effective due to selective observation.
Business Advice: Survivor Stories
Management literature is notorious for survival bias. Books analyzing “great companies” often study only businesses that succeeded, drawing conclusions about their practices without examining whether failed companies followed the same practices.
A famous example comes from Jim Collins’ business bestseller “Good to Great,” which analyzed companies that transformed from average to exceptional performers. Several companies praised in the book, including Circuit City and Fannie Mae, subsequently collapsed or required government bailouts, raising questions about the methodology’s validity.
By studying only “survivors,” such analyses often mistake luck for skill and correlation for causation. They identify practices that might be common among successful companies but fail to note these same practices may be equally common among failed ones.
Napoleon’s Russian Campaign: The Frozen Evidence
When Napoleon invaded Russia in 1812, he began with approximately 450,000 soldiers. Only about 10,000 returned. Historical accounts of the campaign often focus disproportionately on these survivors’ experiences, creating a narrative heavily weighted toward the experiences of those who endured the entire ordeal.
The famous winter retreat from Moscow features prominently in these accounts, with harrowing descriptions of extreme cold and starvation. While these conditions were certainly devastating, survival bias obscures the fact that more of Napoleon’s troops died during the summer advance than during the winter retreat. Disease, heat exhaustion, and Russian guerrilla tactics decimated the Grande Armée before winter arrived.
By focusing primarily on winter survivors’ accounts, historical narratives overemphasized cold as the decisive factor while underrepresenting the many who perished from other causes earlier in the campaign.
Challenging Our Historical Understanding
These examples reveal how survival bias fundamentally shapes our understanding of history. To counter this bias, historians increasingly employ methodologies that actively search for what hasn’t survived, using archaeological evidence, statistical modeling, and cross-cultural comparisons to fill in historical blind spots.
As consumers of history, we should approach historical narratives with healthy skepticism, always asking: What might be missing from this picture? Whose voices weren’t preserved? What failures disappeared from the record?
Conclusion: The Value of Failure
Acknowledging survival bias doesn’t just give us a more accurate view of history—it offers practical wisdom. When we recognize that failure is underrepresented in our understanding of the past, we gain valuable perspective on our own setbacks and the statistical nature of success.
The real lesson of survival bias is that failure is both common and instructive. By seeking out and studying failures rather than focusing exclusively on survivors, we gain insights that would otherwise remain hidden. In business, science, medicine, and personal development, understanding what doesn’t work can be just as valuable as knowing what does.
History’s greatest progress often comes not from replicating past successes, but from analyzing past failures—the very data points that survival bias tends to erase. By actively countering this bias, we develop a richer, more accurate understanding of both history and the present.
As the philosopher George Santayana famously observed, “Those who cannot remember the past are condemned to repeat it.” To that, we might add: “Those who remember only the surviving parts of the past are condemned to misunderstand it.”
