The Lego Bridge Experiment
A few years ago, University of Virginia behavioral scientist Dr. Leidy Klotz was building a Lego bridge with his three-year-old son. One of the bridge’s support columns was taller than the other.
Klotz instinctively reached into the toy bin to find a brick to add to the shorter column. Before he could place it, his son reached over and simply removed one brick from the taller column. The bridge was instantly level, elegant, and stable.
That moment sparked a multi-year series of behavioral psychology experiments published in the prestigious journal Nature. Klotz and his research team tested thousands of people across puzzle-solving, writing, architecture, and cooking. They discovered a universal cognitive blind spot: When humans try to improve anything, our brains systematically default to adding components, completely failing to consider subtraction.
Why Our Evolutionary Brain Defaults to Adding
Why do we default to adding more meetings, more software apps, more laws, and more possessions?
- Evolutionary Biology: For hundreds of thousands of years, survival meant acquiring: more food, more tools, and more shelter. Adding felt like safety.
- Social Signaling: In modern workplaces, adding something (launching a new committee or publishing a 50-page report) is visible and gets you promoted. Removing an obsolete meeting is invisible and rarely rewarded.
- Cognitive Shortcuts: Brain scans show that finding an additive solution requires less cognitive energy than imagining what could be removed.
4 Steps to Master Subtractive Innovation
1. Invert the Prompt: Subtract First
Before approving any new initiative, rule, or tool, make a mandatory policy: “What can we remove first to achieve this goal?” (e.g., Strider balance bikes removed pedals entirely, revolutionizing how toddlers learn to ride).
2. Make Subtraction Visible and Celebrated
Celebrate when an engineer deletes 500 lines of messy code or when a manager cancels a useless weekly meeting. Give subtraction prestige.
3. Create a ‘Stop-Doing List’
Keep a running list of obsolete commitments, toxic habits, and low-yield projects that you permanently abandon to reclaim your energy.
4. Practice Categorical Subtraction
Don’t just trim around the edges. Remove entire categories of friction (e.g., Declare “No-Meeting Wednesdays” or ban internal email in favor of direct async boards).
Leidy Klotz on Overcoming the ‘Sunk Cost Trap’ in Subtraction
Why do companies keep funding failing software projects, and why do people stay in unhappy relationships? Because of the Sunk Cost Fallacy combined with our Addition Bias:
- We tell ourselves: “We already spent $500,000 on this project; we just need to add one more feature to make it work.”
- In reality, the fastest path to profitability is to subtract the failing project immediately and reallocate talent toward high-yield opportunities.
3 Daily Subtraction Experiments to Simplify Your Life
- The 24-Hour Digital Purge: Delete 5 unused apps from your smartphone and unsubscribe from 10 newsletters today.
- The 50% Rule for Meeting Agendas: Cut a 60-minute meeting to 30 minutes, or reduce a 20-slide presentation to 10 slides.
- The Wardrobe Subtraction: Donate every piece of clothing you haven’t worn in the last 12 months.
Summary of Subtract Principles
- Human brains have an evolutionary blind spot: we default to adding complexity when problem-solving.
- Subtraction is faster, cheaper, and more elegant than addition, but requires conscious cognitive effort.
- Create a ‘Stop-Doing List’ and celebrate when unnecessary meetings, code, and rules are permanently removed.
Real-World Case Study: The 10-Line Code Subtraction
A technology company was struggling with a complex checkout software architecture that caused frequent server crashes and customer cart abandonment. Engineers had spent six months trying to add caching layers and error-handling patches. A senior architect looked at the codebase and asked: “What if we subtract the redundant authentication check?” She deleted 400 lines of legacy code.
The checkout process sped up by 80%, server crashes dropped to zero, and quarterly revenue increased by $1.4 million.
3 Commitments for Subtractive Mastery
- Look for opportunities to subtract before defaulting to adding complexity.
- Create and maintain an active ‘Stop-Doing List’ for your business and life.
- Make subtraction visible, valued, and celebrated in your organizational culture.
The Elegance and Power of Less
True mastery is knowing what to leave out. Subtract the noise, eliminate the unnecessary, and discover the profound beauty and freedom of a simple, focused life.
The Superpower of Subtraction
In a culture that constantly shouts for more, the person who masters subtraction holds an unfair advantage. Strip away the friction, clear the clutter, and discover the elegance of less.
3 Subtractive Rules for Innovation
- Ask ‘What can we remove?’ before approving any additive solution.
- Keep a vibrant Stop-Doing List to eliminate obsolete processes.
- Celebrate simplicity and clarity as the highest forms of sophistication.
The Joy of a Subtracted Life
When you subtract what does not matter, what truly matters shines with breathtaking clarity. Simplify your schedule, unclutter your mind, and enjoy the profound peace of less.
3 Subtractive Practices for Everyday Peace
- Eliminate two low-yield tasks from your schedule every week.
- declutter your physical workspace to reduce cognitive friction.
- Focus your best energy on the few vital relationships and goals that matter.
The Untapped Power of Less in Innovation
Subtraction is the secret signature of true mastery. In design, leadership, and personal life, the most powerful move is often removing what is unnecessary so the essential can shine.
Subtraction as a Spiritual Discipline
When you let go of excess possessions, meetings, and commitments, your soul breathes freely. Embrace subtraction as your daily path to clarity, elegance, and peace.
Practical Reflection on the Art of Subtraction
Look around your office and schedule right now. Identify one thing you can remove or cancel today. Experience the immediate lightness and clarity of less.
Summary of the Subtractive Mindset
- Subtraction is a deliberate discipline of removing the non-essential.
- Free up mental and physical energy by creating an active Stop-Doing list.
- Achieve elegance, speed, and focus by stripping away unnecessary noise.
Frequently Asked Questions
What is the central finding of Subtract by Leidy Klotz?
The central finding is that human brains systematically default to adding features, tasks, and complexity when problem-solving, overlooking subtraction as an effective solution.
What was the Lego Bridge experiment?
An experiment showing that while adults tried to level a bridge by adding bricks to the short side, a child solved it faster and better by removing a brick from the tall side.
Why is subtraction rarely used in corporate settings?
Because adding new projects, reports, and committees is publicly visible and rewarded, whereas subtracting obsolete processes is often invisible.
How does subtraction benefit product design?
By stripping away unnecessary features, products become simpler, cheaper, more intuitive, and less prone to failure (e.g., balance bikes or the original iPod).
What is a ‘Stop-Doing List’?
A formal inventory of projects, meetings, and habits that an individual or team deliberately terminates to free up resources.
How does subtraction improve cognitive performance?
Removing notifications, clutter, and commitments clears working memory and reduces decision fatigue.
What is ‘Categorical Subtraction’?
Eliminating an entire category of activities (e.g., no meetings on Fridays or removing all physical clutter from a desk).
What is the single best way to apply subtraction today?
Review your weekly calendar and eliminate or decline at least two recurring meetings that produce zero tangible value.
