162 | Leidy Klotz on Our Resistance to Subtractive Change

Episode Summary

Executive Summary: The episode explores Leidy Klotz’s research showing that people systematically overlook subtraction when trying to improve things, preferring to add rather than remove. Using experiments, examples, and theory, the conversation links this bias to cognition, satisficing, loss aversion, culture, engineering, sustainability, and everyday self-improvement, arguing that deliberately considering less can lead to better designs, systems, and lives.

Main Topics: The subtraction bias (Priority: 5/5): Klotz explains that when people try to improve objects, ideas, or situations, they default to adding elements and often fail to consider removal as an option. Experimental evidence from grids and other tasks (Priority: 5/5): The conversation details lab studies where participants modified computer grids and consistently chose adding over subtracting unless subtraction was made salient; distraction increased the bias. Cognitive mechanisms: satisficing and query order (Priority: 4/5): The discussion ties the bias to bounded rationality and query theory: people consider solutions in an ordered sequence, and once an acceptable additive solution appears, they stop searching. Loss aversion and reframing subtraction (Priority: 4/5): Klotz distinguishes subtractive improvement from loss; subtraction becomes easier when framed as creating a better end state rather than giving something up. Evolutionary and cultural explanations (Priority: 3/5): They explore possible biological and cultural roots, including acquisitiveness, competence display, monumental architecture, and differences across societies, while noting evidence is still limited. Applications to engineering, sustainability, and systems (Priority: 5/5): The episode connects subtraction to climate action, traffic, and other complex systems where removing components can improve performance and reduce unintended consequences. Practical self-improvement and writing/editing (Priority: 3/5): They end by discussing how individuals can use subtraction in schedules, habits, and ideas, and how the challenge of subtracting also shaped Klotz’s own book-writing process.

Key Arguments: Humans tend to think of adding before subtracting when trying to improve a design, even when subtraction would be better. The bias is not just about physical objects like Legos; it appears across ideas and situations when people are asked to make something better. Experimental setups showed that people were not merely reluctant to subtract; many did not even think of subtraction unless prompted. When cognitive load increases, people rely more on the additive default, suggesting subtraction is not the first-accessed mental strategy. The phenomenon fits bounded rationality: people satisfice, choosing the first acceptable solution rather than searching exhaustively for better ones. Loss aversion can block subtraction if removal is framed as loss rather than improvement; reframing the goal helps overcome this. Cultural differences may exist, but current evidence suggests within-culture variation is larger than between-culture variation in the tested samples. In complex systems such as traffic or climate, subtractive interventions can outperform additive fixes because they reduce complexity and unintended interactions. The habit of adding also shapes science and learning, where abandoning old misconceptions can be more powerful than simply layering new information on top.

Data Points: Grid size: 10 by 10 - The computer-based symmetry task used a 10x10 grid with colored and blank squares. Cognitive load task: Press F when a 5 appears - Participants performed a secondary task while doing the grid experiment to increase distraction. Atmospheric CO2: Over 420 ppm - Klotz contrasted current CO2 levels with a safer target for climate discussions. Safer CO2 level: 350 ppm - Mentioned as the approximate level scientists consider safer in the climate example. Donation match: Up to $1,000 - A sponsor message for GiveWell mentioned matched donations for first-time donors. Lives saved: Over 75,000 lives - GiveWell’s impact estimate for donations to recommended charities. Donors: Over 50,000 - GiveWell’s reported donor count. Funds donated: Over $750 million - GiveWell’s reported total amount donated through its recommendations. Book-related omitted words: About 40,000 words - Klotz said this amount of material did not make it into the final book.

Pivotal Quotes: "The whole is something else than the sum of its parts." — Kurt Koffka (quoted by Leidy Klotz): Used to illustrate that improving a system may require transformation, not simple addition. "How do we add cognitive load? How do we add cognitive load?" — Leidy Klotz: Describing how the research team tested the effect of distraction on additive versus subtractive choices. "To gain knowledge, add things every day; to gain wisdom, subtract things every day." — Lao Tzu (as cited by Leidy Klotz): Invoked to connect subtraction with wisdom, reflection, and intentional simplification.

Implications: Listeners are encouraged to explicitly ask what can be removed, not just added, when solving problems, designing systems, or organizing life. The broader lesson: better outcomes may come from deliberate subtraction in design, policy, and personal habits.