In This Issue
Winter Issue of The Bridge on Complex Unifiable Systems
December 15, 2020 Volume 50 Issue 4
The articles in this issue are a first step toward exploring the notion of unifiability, not merely as an engineering ethos but also as a broader cultural responsibility.

Complexity Blind Spots

Friday, December 18, 2020

Author: Susan M. Fitzpatrick

Although scientists and engineers know that many of the hardest problems daunting society and in dire need of solutions are complex, the tendency in the academic research community is to pursue its work as though problems are simple.

Seeing Holes—and Their Absence

Complex systems researchers David Krakauer and Geoffrey West (2020) have offered a compelling insight into why the traditional practices of science and engineering struggle to seek meaningful solutions that address complex problems: Humans have a cognitive blind spot that causes us to ignore what is not seen. Krakauer and West illustrate this point with a World War II story about the analysis of the location of bullet holes in planes returning from missions.

Faced with the dilemma of balancing the need to armor planes from enemy bullets without making the planes too heavy, the military called in experts to study the pattern of bullet holes in returning planes and make recommendations about armoring future planes. The experts at first suggested the obvious: the military should add armor to the areas most frequently damaged. Makes sense, yes? Well, maybe not.

One of the experts consulted, the statistician Abraham Wald, pointed out that since the planes analyzed had all made it back, the parts of the planes with bullet holes were those that could sustain damage and still fly. What if, Wald asked, the parts of the returning planes that showed no damage were those essential for continued functionality? What if the planes that did not return were those that sustained damage in these essential areas?

Persuaded by Wald’s thinking, the military armored the parts of the planes that typically returned with no damage. It worked. Protecting the essential components of the planes (e.g., engines) allowed aviators to adhere to weight limitations while decreasing losses and saving lives.

What the Pandemic Has Revealed

Krakauer and West use this powerful World War II example to direct attention to the damage not -attended to during the covid-19 global pandemic, what they describe as “the deeper nature of the crisis—the collapse of multiple coupled complex systems.”

From my perspective, the covid-19 global pandemic has revealed the fragility and brittleness of any number of the engineered systems that we rely on, as individuals and as a society. Be it transportation or health care, education, or the food supply chain, it can all fall apart quickly when shocked.

Most importantly, although the virus is where our attention is being drawn, the pandemic is not the cause (in part it is more likely a result) of societal fragilities. The pervasive system failures result from willingness to ignore the damages we do not see. In almost every one of the sectors above, we are where we are because we engineered systems ignoring the complexity of the problems they were designed to solve.

Much of 20th and 21st century science is dominated by reductionist thinking rather than complex systems science thinking. These two robustly different traditions influence the way questions are framed, solutions pursued, and investments made in the infrastructure for pursuing research. The pressing problems pertinent to the quality of human life in terms of climate, health and wellbeing, social structures and inequities, economic stability, and educational effectiveness are complex and require approaches that honor complexity. Sadly, acting as though the complex is simple will not make it so.

Unseen Costs of “Efficiency”

By prioritizing “efficiency,” built systems have eliminated the traits, such as redundancy, that natural complex systems have evolved to remain robust and adaptive. Centralized hub-and-spoke configurations are “efficient” only because of the damages and fragilities we do not see.

  • Networked but nonadaptive transportation systems often fail to move people from where they are to where they want to be on a good day. Introduce natural or man-made disruptions and movement can grind to a halt.
  • Sophisticated instructional technologies claim to solve the need to efficiently advance educational goals but, when tested, their effectiveness is stymied by an inability to ensure equal access and determine meaningful outcomes.
  • Industrialized food provides a plentiful calorie-dense diet, but its nutrient-poor nature is adding to the health issues faced by many of the world’s most vulnerable citizens.
  • Funders have spent billions of dollars pursuing medical interventions using highly artificial and over-constrained laboratory models that efficiently produce data but fail to deliver effective therapies because the reductionist science ignores the reality that diseases occur in the context of a complete adaptive organism.

In all of these examples and in many other arenas of our engineered world, the damages we do not see are the costs to individuals and to society when perturbations knock our fragile systems to their knees.

Looking Ahead

Could we “build back better?” In a word, yes. But the difficulties of doing so cannot be swept under the carpet. Progress and improvement require will and dedicated effort to shift the dominant school of thought toward one that embraces both robustness and adaptation. New values need to be adopted, rewarding and incentivizing the difficult task of meeting global needs rather than fulfilling parochial goals. Doing so means educating a generation of scientists and engineers in the theories, concepts, tools, and mathematics of complex systems science.

The massive shock that covid-19 dealt the global community is already creating an opportunity for novelty and creativity. Airlines and other transportation sectors are reconsidering the distributed point-to-point model over the centralized hub and spoke. Clinical trial specialists are exploring opportunities for carrying out their work in “messy” community healthcare settings. Urban vertical farms are looking to grow healthy, nutritious food locally, reliably, sustainably, and affordably. Schools are seeking effective teaching strategies that serve all children and will meet the needs of mid-21st century learners.

Perturbations allow novelty to be introduced into stable systems. The pressures of war allowed the military to consider an unintuitive solution and lives were saved. The time is now for the scientific and engineering communities to likewise identify the damage we are not seeing, advance progress by fulfilling the demands for new knowledge, and engineer solutions that better serve all of us.


Krakauer D, West G. 2020. The damage we’re not attending to. Nautilus, Jul 8.

About the Author:Susan Fitzpatrick is president of the James S. McDonnell Foundation.