Surface Area
Possessions, relationships, commitments, and beliefs all create demands on your attention. Surface area is a metaphor for that exposure: reducing it can ease maintenance, while expanding it can bring useful connections and ideas.
THE IDEA
Surface Area
Surface area measures the area of an object's outer surfaces. For the same amount of sugar, loose granules dissolve faster than a cube because more sugar is in contact with the water. A large gift generally needs more wrapping paper than a small one. These physical examples suggest a metaphor for the demands created by what we own, do, and engage with.
One house needs upkeep. Another adds maintenance and may also add travel or coordination between properties. More friends can mean more demands on a finite amount of time; more assets can mean more accounts and decisions to manage. Beliefs create another kind of exposure when we feel obliged to defend each one. Hiring assistants, property managers, or a family office can reduce the work we do personally, though overseeing that help takes attention too.
When commitments outgrow our capacity to manage them, reducing them may help more than finding extra time. Expansion can also become part of an identity: the “busy person” with a hand in every project, or the guy with four houses. Keeping up with someone else's possessions or schedule can add obligations we do not particularly want.
In physical systems, more surface area can be useful. Powdered reactants often react faster than lumps because more material is exposed to the other reactants. Small sticks catch fire more readily than dense logs. Alveoli give lungs a large area for gas exchange; folds and villi increase the intestines' area for absorption. A lower surface-area-to-volume ratio can help an animal retain heat, and curling up when cold reduces exposed area. Which arrangement helps depends on the interaction we want to encourage or limit.
The metaphor also applies to projects. External libraries give software a larger “surface area” of dependencies to maintain. Fewer dependencies can simplify maintenance, though replacing a reliable library with custom code can add work. A project involving ten teams has more coordination demands than a project involving one, but those teams may also provide expertise it needs.
Fresh ideas often require more exposure: meeting people outside our usual circle, exploring another discipline, or inviting criticism of our work. The extra contact has costs as well as benefits.
I know billionaires with two houses, not ten. Most of my close friends have only four or five close friends—everyone else is a friend in the loosest sense. The most productive people I know at work focus on one or two things, not five. Those observations suggest a useful question: which commitments deserve the attention they require? Keeping a smaller surface area takes work too, especially when it means declining something appealing.
When to use it
When launching a startup, compare the value of each outside service or partner with the dependency and coordination costs it introduces.
A salesperson looking to generate more leads should increase their surface area by networking broadly, attending events, and being active on multiple platforms.
Comparing the administrative simplicity of a portfolio with its exposure to losses; fewer holdings can reduce upkeep while increasing concentration risk.
In software architecture, limit exposed interfaces to what users need and examine the security risks of each.
Personal simplification: audit commitments, possessions, and relationships to eliminate those that drain energy without proportional value.
Business strategy: before launching a new product line or office, assess whether the increased surface area (logistics, management, coordination) will yield net benefit.
Financial planning: compare the overhead of managing a complex portfolio of real estate, stocks, and businesses against a simpler, consolidated approach.
Time management: limit active projects to leave enough attention for the work and relationships you value.
A startup deciding how transparent to be with its product roadmap to investors and the public.
An individual choosing how many new social events to attend each month to expand their network while preserving personal time and privacy.
A research lab evaluating whether to share preliminary data openly to foster collaboration or keep it confidential to avoid being scooped.
A company debating whether to diversify into a new market segment, increasing its market surface area but also spreading resources thin and exposing itself to unfamiliar risks.
FROM THEORY TO EVERYDAY LIFE
In practice
Sugar dissolving
A teaspoon of loose sugar dissolves much faster than a sugar cube because the smaller granules have a larger overall surface area in contact with water.
Fire starting
It’s easier to start a fire with many small sticks than a few logs, because the small sticks have more surface area exposed to oxygen, facilitating a faster reaction.
Lungs and intestines
Alveoli provide a large surface for gas exchange in the lungs. Folds and villi increase the surface available for nutrient absorption in the intestines.
Adaptation to cold
Animals in cold climates often have a lower surface-area-to-volume ratio (e.g., stockier bodies) to reduce heat loss, while animals in warm climates have higher ratios to dissipate heat.
Scrunching up when cold
When you're cold, you instinctively curl up to reduce your exposed surface area, minimizing heat loss to the environment.
Code dependencies
Fewer external dependencies can make a software program easier to maintain by reducing the number of updates and compatibility changes to track. A reliable library may still require less work than maintaining an equivalent feature yourself.
Project dependencies
A project that depends on multiple external teams (large surface area) is more likely to face delays and coordination failures than one with fewer dependencies.
Houses and Maintenance
A second house adds another roof, utilities, and other upkeep. Travel between properties or arranging remote care may add coordination costs beyond the maintenance of each house.
Social Circles
If you have only a few close friends, you can invest deeply in those relationships. As your circle grows, the time you can give each person shrinks. The surface area of social obligations can lead to shallow connections and scheduling stress.
Wealth and Complexity
Wealth spread across several asset classes, accounts, or legal structures can require substantial administration. Hired help can take on much of the work, while the owner still needs to decide how that help is supervised.
Identity as Surface Area
Labeling yourself as someone who is always busy or owns multiple properties becomes part of your identity. This identity then demands behaviors that maintain that surface area—taking on more projects, acquiring more—which can lead to burnout.
Open-Source Software Strategy
Releasing a project as open source invites contributions and public scrutiny. That can improve the code, but reviewing contributions and responding to reports takes work. Public access also lets both defenders and attackers inspect it.
Social Media Presence
An individual chooses to share professional achievements and personal opinions widely on social media (large surface area). This can lead to networking opportunities, career offers, and meaningful connections. But it also attracts online criticism, privacy invasions, and reputational risks if missteps are amplified.
A MOMENT TO REFLECT
Put it to work.
In what area of your life or work are you currently overexposed, and how could you reduce your surface area to decrease risk?
Where might you benefit from increasing your surface area to accelerate growth or learning?
Consider a project you're involved in: how many dependencies does it have? How could you reduce its surface area to improve its chances of success?
Which possession or commitment takes more upkeep than you expected when you acquired it?
How does your self-identity contribute to the surface area you maintain?
What would you gain and lose by dropping one current commitment?
Which responsibilities have you delegated, and what oversight do they still require?
Who outside your usual circle could help you understand a problem you are working on?
For a current project, which dependencies provide essential expertise and which add avoidable coordination?
CONTINUE THE CONVERSATION
Source texts
- The Great Mental Models Volume 3 Systems and Mathematics
- The Great Mental Models Volume 3 Systems and Mathematics
- The Great Mental Models Volume 3 Systems and Mathematics
- The Great Mental Models Volume 3 Systems and Mathematics