Mental Pivot #66: Cascading Whys
Digging deeper to find the root cause, Stoic rules for life, and the frequent weirdness of reality.
Most problems do not call for complex statistical analysis, but instead require painstaking, detailed problem-solving…
What is the root cause of the problem? The answer lies in digging deeper by asking why the problem occurred. Asking “Why?” five times requires taking the answer to the first why and then asking why that occurs. Typically, the process of asking “Why?” leads upstream in the process.
— Jeffrey K. Liker, The Toyota Way (2003)
The Lincoln Memorial in Washington, D.C. is a neoclassical monument that was completed in 1922. The building uses a variety of materials: granite for the terrace walls and lower steps, marble for the columns, limestone for the interior walls and columns, and pink marble for the flooring.
We build monuments to stand the test of time, but by the late 1980s, the National Park Service was concerned about the deterioration of the Lincoln Memorial and the nearby Jefferson Memorial. The popular monuments were crumbling; inspectors found cracks in the stone columns and foundations. Improper maintenance, overuse, and environmental wear-and-tear were taking a toll. In early 1990, the situation grew more dire when a 50-pound chunk of a volute capital in the Jefferson Memorial broke from its column and crashed to the ground (fortunately this occurred in the early morning and no one was hurt).
To address the problem, the Park Service conducted a $2 million study that enlisted outside consultants—architects, structural engineers, and even an entomologist—to get to the root cause of the building’s woes. Based on the study, the greatest threat to the marble and limestone in the monument was water: rainwater, groundwater, and water used to clean the building surfaces. Marble and limestone are porous; water can seep into the rock and form cracks. Given enough saturation and time, this can lead to structural failure.
Improved gutters and drainage addressed the rainwater problem. Shoring up the foundation and basement walls helped with the groundwater problem. But the frequent cleanings were particularly vexing. Why did the memorials need so much cleaning? It was one of many questions the Park Service sought to answer.
The simple answer was that a layer of unsightly slime would regularly form on the exposed surfaces of the monument—particularly on the exterior walls and columns. But that prompted another question, where did the slime come from and why was its buildup so rapid and incessant?
To help answer that question, the Park Service turned to entomologist, Donald H. Messersmith. His work on the Lincoln Memorial went on to become a favorite case for business writers, students of root cause analysis and Toyota’s “Five Whys” system (an iterative sequence of questions to probe for a deeper causal answer).
The conventional narrative describes a sequence of investigative questions to get to the bottom of this mystery. Each question functions to uncover a more fundamental truth underlying a long chain of cause and effect.
It looks something like this:
Where does the slime on the monument come from?
Answer: It’s the result of multiple factors, all interrelated. Most visible are the sparrows and starlings which are attracted to the monument. They roost on the building and make a mess with their droppings.Why are the birds attracted to the monument?
Answer: They come because of the abundant food, especially the spiders.Why are the spiders attracted to the monument?
Answer: Like the birds, they are drawn by food, small flies known as midges. The midges deposit their eggs on the walls, leave droppings on the walls, and perish on the walls. The spiders consume these remains and, in turn, leave their own droppings, webs, and remains.Why are the midges attracted to the monument?
Answer: Swarms of midges are attracted to the lights used to illuminate the monument.
Based on this analysis, a solution presented itself: eliminate the midges. Doing so would curtail the bug swarm’s cascading consequences and, in turn, require less frequent and less intensive surface cleaning. Less cleaning would result in less water used on the monument’s porous stone surfaces, which would mean reduced wear and tear on the building. Midges are crepuscular, which means they are most active during twilight (as opposed to organisms that are diurnal or nocturnal). Therefore, Messersmith’s recommendation to the Park Service was simple: delay turning on the lights by an hour to avoid attracting midges before nightfall.
The solution worked during the initial pilot. The midge swarms were significantly curbed. And, in a news article from the Washington Post from 1990, one Park Service director expressed hope that, instead of cleaning the entire memorial twice a year, he might be able to do so once every three years.
Present-day observers view Messersmith’s work as a resounding success, but the reality was a bit more nuanced. First, his solution was just one of many that the Park Service enacted to address the monument’s deterioration (they still had groundwater and rainwater to deal with as well as other problems like vandalism, litter, pollution that midge mitigation couldn’t alleviate). Second, his solution wasn’t permanent. In the mid-1990s, the Park Service turned the lights back on at twilight to appease disappointed tourists who wanted the memorial illuminated earlier. Even the most sensible plans can fall prey to the vicissitudes of human wants.
Still, the story of the Lincoln Memorial and the midges is a fun one because it demonstrates the not-so-obvious sequence of cause and effect that sometimes lies behind the answers to perplexing problems. The connection between marble erosion and swarming midges at dusk is not intuitive; it’s an idea that needs to be teased out by a more rigorous and thoughtful exploration. Even if the Park Service’s failure to permanently implement Messersmith’s was disappointing, the process, as recounted today, remains an exemplar of inquiry and problem-solving.
When confronted with a tricky question, Messersmith’s midges remind us to interrogate the problem by digging deeper by asking “why?” repeatedly. Doing so might result in surprising answers.
Now onto this week's recommendations…
Thinking Tools:
12 Stoic Rules for Life: A solid overview of important Stoic concepts from Ryan Holiday’s Daily Stoic website. A small sampling of the rules: “only focus on what’s in your control,” “constantly ask, ‘is this necessary?’”, and “turn obstacles upside down.”
My Notebook System: Dave Gauer reflects on 10 years of writing in analog notebooks for journaling, sketching, and idea capture (he then digitizes some of his notes for easier searching and review). Interestingly, he started off with a much more rigorous system and eventually transitioned to more free-form note-taking.
Optimal Quitting: “When we ignore opportunity cost, we often squander that most precious limited resource of all: time.”
Reality Is Very Weird and You Need to Be Prepared for That: An article that explores the fascinating scientific history behind the cure for scurvy; it’s presented as a prime lesson of how “real explanations will sometimes sound weird, crazy, or too complicated because reality itself is often weird, crazy, or too complicated.” Also offers some ideas for confronting contradictory evidence and avoiding being overly dismissive of unusual explanations.
Reading Enrichment:
Misidentifying Talent: Organizations want to hire the most talented people, but how they go about accomplishing that is often stymied by “incorrectly honed gut feelings” and an over-reliance on conscious (and unconscious) biases. Case in point: baseball scouts often remark on a prospect’s facial features in their reports, but does this characteristic have any practical correlation with performance?
The Rise of Big Tech May Just Be Starting: “The pandemic illustrated how much room there still is in our lives for adding even ore tech—for our screens to become the primary portal through which a handful of companies capture a slice of everything we do.”
Talking Shop: The Transformation of Commerce: Rex Woodbury spotlights key areas of growth in online commerce including livestream commerce (which is huge in China), social commerce, new customer acquisition channels, micro-influencers, and creator-led brands (think Kim Kardashian’s SKIMS brand or Logan Pauls’ Gatorade competitor).
What Is the Metaverse?: A gentle introduction to tech’s current buzzword du jour. The author breaks the concept into four key concepts: spatial computing (think augmented reality, virtual reality, immersive computing and similar interfaces), game engines (as critical development tools), virtual environments, and virtual economies.
Why the Nineties Rocked: “Travel back in time to a magic lost world called the 1990s, a world free of 9/11, communism, COVID-19, and an internet that turned nasty on us.”
Odds & Ends:
Ranking the Life Expectancy of Humans vs. 49 Other Animals illustrates a wide range of lifespans, from the short 1-year lifespan of the house mouse (Mus musculus) to the immortal jellyfish (Turritopsis dohrnii). The latter species is capable of reverting from maturity back to a sexually immature stage of development—a process that can go on indefinitely (so long as the organism doesn’t perish due to other factors, such as predation).
What Makes Writing More Readable is a wonderful demonstration of plain language, described as “a style of writing that uses simplified sentences, everyday vocabulary, and clear structure.” The piece also looks at readability formulae, which score the accessibility of written prose based on factors such as syllable count, word familiarity, sentence length, and other factors.
Wendover Productions is a YouTube channel that produces short but well-researched short documentaries (10-20 minutes typically) that explain how the world works. Interesting recent releases include “How Cell Service Actually Works,” “How Airlines Quietly Became Banks,” and “The Incredible Logistics of Grocery Stores.”
Cross-Promotions:
Refind is a content discovery tool that sends curated articles to your email inbox or via mobile app (iOS and Android). Focus your attention on what’s really relevant to you.
The Sample: A newsletter discovery tool. Based on your interests and feedback, The Sample sends a new newsletter recommendation to your inbox on a daily or weekly basis.
Thank you for subscribing to the Mental Pivot Newsletter. If you’re enjoying it, be sure to share it with your friends and spread the word.
I want to be able to deliver a top-notch newsletter to all of you. To that end, I’d love to hear your thoughts on what’s working, what doesn’t, and things you’d like to see more of. You can reach me by replying directly to this email or by adding a comment on Substack.
If this newsletter was forwarded to you, visit this link to subscribe.
This one was fabulous! Thanks so much, going to share and pass on the love.