Episode Summary
Executive Summary: Michael Shermer and Leidy Klotz discuss Klotz’s book Subtract and the cognitive bias toward adding rather than removing when solving problems. They explore evolutionary and cultural roots of this tendency, evidence from experiments and natural settings, and real-world applications in design, regulation, climate policy, racism, and information display.
Main Topics: The science of subtraction: Klotz explains his research showing that when people try to improve systems, they usually think of adding before subtracting, even when removal is the better solution. Behavioral science and design: The conversation frames subtraction as a design problem, arguing that engineers and designers should integrate behavioral science earlier rather than treating it as an afterthought. Evolutionary and cognitive reasons for adding: They discuss loss aversion, endowment effects, sunk-cost style thinking, and the idea that adding may have been adaptive in environments where humans lacked abundance. Examples of effective subtraction: They examine the Vietnam Veterans Memorial, the Embarcadero Freeway removal, balance bikes, and Tufte/Feynman-style information design as cases where removing elements improved outcomes. Complex systems and regulation: The discussion uses bike-race rules, bureaucratic growth, and state regulation as examples of how systems accumulate rules over time and may benefit from deliberate pruning. Climate change and social justice: Klotz argues that climate action and anti-racism can benefit from subtraction—reducing emissions, removing barriers, and eliminating systemic obstacles—rather than only adding new programs.
Key Arguments: People systematically overlook subtraction when trying to improve something; the first idea is usually to add. This bias is not just about loss aversion after subtraction is considered; often subtraction is never considered at all. Designers, engineers, and policymakers should treat subtraction as an active option, not a fallback. Reminders and cues can increase subtractive thinking without reducing additive thinking. Many systems become more complex over time, creating fruitful opportunities for subtraction to improve performance. Not every problem is solved by subtracting, but many underperforming systems can be improved by removing unnecessary elements or constraints. Information design should maximize clarity by removing clutter, as shown by Tufte and Feynman examples. Climate policy should include removal strategies such as decarbonization and CO2 removal, not just slower growth or adding new technologies. Anti-racism work can include subtracting barriers and biased practices, not only adding diversity initiatives.
Data Points: Research scale: tens of thousands of hours - Klotz describes the experimental program behind the subtraction findings as extensive and collaborative. Book length reduction: ~40,000 words saved - Klotz says he deleted a large amount of material while writing Subtract. Organ donation example: higher opt-out rates - Used to illustrate how defaults can materially change behavior in nudge design. Rules in Race Across America: 1 page initially - Shermer recounts how the original race rule sheet was extremely short before expanding over time. Rules growth: 17 to 20 times as long as 1950 - Klotz cites a statistic about the growth of regulations/rules over time. Göbekli Tepe age: about 11,000 years old - Used to discuss early monumental architecture and the origins of civilization. Penalty shootout count: 19 years old - Shermer mentions a young player in a Euro Cup final as an example of pressure in penalty kicks. Vietnam Veterans Memorial names: 58,000+ names - The memorial’s name wall conveys the scale of loss through subtraction and simple design. Cognitive load task: number line scrolling with keypress on 5s - An experiment used distraction to test whether people default to additive solutions when mentally loaded. Organ donation incentive: $100 - Shermer references companies offering cash incentives to encourage vaccination. Employer vaccine incentive: $200 per employee - Klotz mentions a mining company paying workers to get vaccinated. Vaccination uptake estimate: 75% - The mining company example reportedly achieved about three-quarters participation due to the incentive. TED early guidance: 10 items on a mouse pad - Shermer contrasts an early simple TED instruction sheet with a later 37-page PDF. TED later guidance: 37 pages - Used to show bureaucratic/organizational accumulation of rules and instructions.
Pivotal Quotes: "when we're thinking about how we change something or how we make something better... we first think about what we can add" — Leidy Klotz: Core statement of the book’s thesis about additive default thinking. "There's no such thing as a neutral choice architecture" — Leidy Klotz: Explaining why defaults and menu design inevitably shape outcomes. "Maximize the data or the ink to information ratio" — Edward Tufte (as cited by Klotz/Shermer): Presented as a key principle for clear, subtractive information design.
Implications: For listeners, the lesson is to actively ask what can be removed before adding more—whether in work, policy, design, or personal life. For organizations, subtraction may improve efficiency, clarity, and fairness without sacrificing effectiveness.