Subtract
The Untapped Science of Less
Book Edition Details
Summary
"Subtract (2021) explores subtraction as a way to make positive change. It examines the human love affair with adding and having “more” – and it explains how our brains and environments work against subtraction. "
Introduction
When faced with problems, why do we instinctively add rather than subtract? Whether it's cluttering our schedules with more meetings to improve productivity, adding new rules to fix organizational issues, or piling on features to enhance a product, our default response seems hardwired toward "more." Yet some of history's most transformative solutions have come through taking away rather than adding. This counterintuitive approach to problem-solving reveals a profound blind spot in human thinking. While we naturally see opportunities to add, improve, and build upon existing systems, we consistently overlook the power of subtraction. The consequences of this oversight ripple through every aspect of our lives, from our overstuffed homes and overwhelming to-do lists to inefficient organizations and unsustainable cities. Understanding why we neglect subtraction and learning to recognize its hidden potential can revolutionize how we approach change. By developing the skill to see what can be removed, simplified, or eliminated, we unlock a more efficient path to improvement that often requires less effort while delivering greater impact. This shift in perspective transforms not only our external circumstances but also how we think, learn, and navigate an increasingly complex world.
The Missing Option: Why We Overlook Subtraction
When three-year-old Ezra and his father sat down to build a Lego bridge, they faced a common engineering challenge: the support towers were different heights, making it impossible to span them. The father's instinct was immediate and familiar—reach for another block to add to the shorter tower. But as he turned back with the additional piece, he discovered his toddler had already solved the problem by removing a block from the taller tower. This moment of surprise revealed something profound about human cognition. The father, despite years of education and professional experience, had defaulted to addition when subtraction offered a simpler, more elegant solution. Intrigued by this pattern, researchers began investigating whether this bias toward adding might be universal. Through thousands of experiments involving Lego structures, word puzzles, travel itineraries, and abstract grid patterns, the evidence became overwhelming. Participants consistently chose to add rather than subtract, even when removing elements would have been objectively better. When asked to improve a packed Washington D.C. travel schedule with fourteen activities crammed into a single day, only one in four people removed activities despite the obvious overload. The root of this oversight lies in how our minds access different types of solutions. Adding feels natural and immediate—we can easily imagine what more looks like. Subtraction requires deeper mental effort, forcing us to envision absence rather than presence. When researchers provided subtle cues reminding participants that removal was an option, success rates for subtractive solutions doubled. We don't avoid subtraction because it's inferior; we avoid it because we literally don't think of it.
From Freeways to Systems: Making Less Visible
For decades, San Francisco's Embarcadero Freeway stood as a concrete barrier between the city and its magnificent waterfront, blocking views of the bay and creating a gray shadow over what should have been one of America's most beautiful urban spaces. Despite growing criticism, the double-decker highway carried tens of thousands of vehicles daily, making its removal seem both impractical and economically devastating. Sue Bierman, a former music student turned city planning commissioner, spent nearly a decade studying this urban problem. Her commission analyzed traffic patterns, economic impacts, and quality-of-life measures, ultimately recommending the radical solution of complete removal. When put to public vote, the proposal failed decisively—two voters opposed removal for every one who supported it. The 1989 Loma Prieta earthquake changed everything. The damaged freeway became a safety hazard and a costly burden to repair. More importantly, the collapse of a similar structure in Oakland had killed dozens, demonstrating the deadly risk of elevated concrete highways during seismic events. With the context transformed, city supervisors narrowly voted to demolish the freeway. The results exceeded even supporters' expectations. Rather than creating traffic chaos, the removal actually improved circulation as drivers adapted to alternative routes. The decade following removal saw a 50 percent increase in housing and 15 percent growth in jobs around the waterfront. What had been an eyesore became one of the world's most visited urban spaces, complete with palm-lined promenades and harbor seal viewing areas. This transformation illustrates a crucial principle about systems thinking. In complex networks—whether traffic systems, organizations, or ecosystems—removing elements can sometimes improve overall performance more effectively than adding them. The freeway removal worked because it eliminated a bottleneck and allowed the natural flow of the city to reassert itself. When we're stuck thinking about individual components, we miss these system-level opportunities for improvement through subtraction.
Anthropocene Lessons: Subtracting for Our Planet
Costa Rica's journey toward carbon neutrality began with a radical act of subtraction that shocked the international community. In 1949, this small Central American nation abolished its military entirely, redirecting war funds toward education, healthcare, and environmental protection. This foundational removal of military spending created space for a different kind of national development. When climate change emerged as a global crisis, Costa Rica again chose the path of subtraction. Rather than simply adding renewable energy sources while maintaining existing practices, the country implemented a comprehensive stop-doing strategy. They halted all oil extraction, eliminated deforestation incentives, and began paying landowners to remove carbon dioxide from the atmosphere by growing forests instead of cattle ranches. The results were transformative. Costa Rica now generates nearly 100 percent of its electricity from renewable sources, has doubled its forest cover since the 1980s, and ranks as one of the world's greenest and happiest countries. Citizens enjoy higher life expectancy than Americans despite having a fraction of the per capita income, demonstrating that subtraction-based development can improve quality of life more effectively than pure economic growth. This environmental success story reveals how subtraction can address seemingly intractable global challenges. While most climate solutions focus on adding clean technologies, Costa Rica's approach emphasizes removing harmful practices first. They've shown that subtracting fossil fuel dependence, deforestation, and military spending creates space for natural systems to heal and human societies to thrive. The lesson extends beyond environmentalism. When facing complex, systemic problems, our instinct to add solutions often compounds the original issue. Costa Rica's experience suggests that identifying and removing the root causes of problems—whether carbon emissions, social inequality, or resource depletion—can be more powerful than layering on additional fixes. Sometimes the most radical act is not building something new, but having the courage to eliminate what no longer serves.
Information to Wisdom: The Art of Mental Subtraction
The average American encounters one hundred thousand words daily—more than contained in most books—yet we struggle to convert this information deluge into meaningful understanding. Email inboxes overflow, news feeds provide endless updates, and our devices buzz with constant notifications, creating what researchers call "information anxiety." The problem isn't scarcity of knowledge but rather our inability to subtract the irrelevant from the essential. An engineering student discovered this principle while facing a crucial mechanics exam. After struggling with poor grades despite diligent studying, he realized he'd been trying to memorize dozens of complex equations and tangential concepts. Before his final exam, he stripped the course down to its essence: Newton's second law and a few application rules. Everything else could be derived from these fundamentals. This mental subtraction transformed his understanding, leading to the highest grade in the class. This experience illustrates how learning often requires unlearning—removing misconceptions, outdated models, and unnecessary complexity to make room for deeper comprehension. The most effective students and professionals aren't those who accumulate the most information, but those who can identify and eliminate what doesn't matter. Like pruning a garden, removing extraneous knowledge allows the most important insights to flourish. The digital age has amplified this challenge exponentially. We can access virtually any information instantly, but our cognitive capacity remains limited to processing about seven items simultaneously. Success increasingly depends not on gathering more data, but on developing the wisdom to know what to ignore. The most productive people have learned to subtract inputs—unsubscribing from newsletters, avoiding certain websites, and saying no to information that doesn't serve their core purposes. Libraries have long understood this principle through the practice of "weeding"—regularly removing outdated or unused books to make space for more valuable additions. Similarly, our minds require conscious curation. By deliberately subtracting irrelevant information, we create mental space for deeper thinking, creativity, and genuine understanding. In an age of infinite information, the rarest skill may be knowing what not to know.
Summary
The key insight emerges clearly: we possess a cognitive blind spot that prevents us from seeing subtraction as a path to improvement, causing us to overlook some of our most powerful solutions. Start noticing when your instinct defaults to adding, then pause to consider what might be removed instead. Practice mental subtraction by identifying the essential elements in any situation and questioning what's truly necessary versus what's simply familiar. When facing complex challenges, ask not only "What can we build or add?" but also "What barriers, rules, or elements could we eliminate?" The most transformative solutions often involve taking away rather than piling on, whether in your schedule, your organization, or your thinking patterns.
By Leidy Klotz
