When I talk about my research, nobody disputes that, when we try to improve something, we often take away. People nod in recognition when I say we keep piling up “to-dos” when what we need are “to-stops,” or when we build incentives for good conduct ... but fail to remove the barriers to it. It sounds right when I note that federal regulations are 17 times longer than they were in the 1950s; and that, in patent titles, “additive” synonyms appear about three times as often as “subtractive” ones. Adding, by default, feels natural.
One explanation, as my colleagues and I showed in our new research: People think about adding first and, as a result, regularly miss subtractive changes. The result was steady and rigorous enough to land on the cover of Nature. And judging by the response in mainstream media, on Twitter, and in my old-school face-to-face conversations, everyone seems to agree that overlooking a basic way to create change in a system is a major problem.
Still, I keep hearing one objection. And it is aimed at something I have never said, namely that subtraction is superior to addition. It is a simple straw man to construct. After all, I did this research, my book is called Subtract, and I have even been labeled a “subtraction czar.” So, to avoid any misunderstanding, I have learned to say early and often that there are meetings, rules, and even highways that absolutely should NOT be subtracted.
That said, if subtracting is about as valuable as adding — yet happens much less often — then there is unused potential. Pablo Picasso, after all, defined art as the “elimination of the unnecessary.” The more is added, the more chances there are for artistic elimination. Here is a more tangible case. Across the globe, pocket parks are helping cities become more livable. These small parks are usually “made” by subtracting one (often derelict) building. What makes them distinctive is the adding that frames them. In a concrete jungle, they are a green oasis. The same idea works at other scales and across objects, ideas, and situations. The streamlined iPhone pleases users in a world of feature creep. Removing an all-hands meeting creates room for deep work from otherwise packed calendars. Meditation brings wisdom to podcast-saturated minds.
To unlock this unused power of subtraction in the future, we need to understand why we have not welcomed it in the past. One likely explanation for why adding has become our first impulse is that we live in a world that has trained and rewarded this mental shortcut. As any armchair physicist can tell you, we are surrounded by a universe that is constantly adding complexity, under the second law of thermodynamics. Biologically, our animal urge to obtain resources (like food) and to signal competence (by visibly altering our surroundings) can tug us toward more. Of course, as thinking humans, we do not have to blindly follow the route set by physics or evolution. But even if we resist thermodynamics and our instincts, more recent cultural forces also push against subtraction. Human civilization is almost defined by addition: of technologies, of education, of culture.
We have been adding for a long time, and for a long time that has made sense. But our instincts to add and our cultures of more are now filling up our minds, cities, and schedules. The problem lies in how we think — and fortunately, so do the solutions — including one that sits at the root of why I keep reminding people that paying attention to subtraction does not mean I am against adding.
The false choice of add OR subtract
To stop missing a basic kind of change, to tap the power of subtraction — whether for our minds, organizations, and cities — we need to shift from thinking add or subtract to thinking add and subtract. The add or subtract framing pushes us to try to resolve an apparent contradiction. If A is true, then not-A must be false. If I appreciate subtracting, then I must dislike adding. Resolving contradiction is not a bad thing. Doing that has supported reasoning at least since Aristotle, who argued that if one idea contradicted another, then one of the ideas had to be discarded.
We owe this logical reasoning for all kinds of scientific advances: everything from our single, repeatable, biological classification system to the mathematical logic that produced modern computers.
So it is working, right? Well, not completely. The trouble arises when we try to resolve contradiction between ideas that are not actually in conflict. As we have seen, the question is not whether biological or cultural forces explain our adding. Both have an overlapping role in our failure to subtract. Debating which is the real culprit only wastes time and pulls us away from learning how we might do better. The question is not, “Should we add or subtract?”, it is “How do we use both?” Our Nature research shows that people often add but then quickly move on, failing to consider even better, higher-order subtractions. That leap straight to adding would not necessarily be a problem if people then considered subtracting. If more makes things better, then maybe less can too.
This move to an add AND subtract mindset is difficult, but not impossible. If you take your design cues from science, try changing your metaphor. Be less like the second law of thermodynamics, endlessly adding. Instead, follow evolution, which uses both additive adaptations and subtractive selections. Then, new meetings on your calendar are something to try, and to select out when they become useless appendixes. If you want mathematical motivation, consider that less can literally be more net change. Imagine you edit four lines of code by adding one. Now that you have five lines of code, one line makes up 20% of the total. But if you change those four lines of code by subtracting one, then you are left with three lines of code, and one represents 33% of the total. Relative to the end state, the very same change is larger when it leaves you with less. Finally, if you prefer pithy quotes, consider one attributed to the Chinese philosopher Lao Tzu that has endured (because we otherwise overlook subtraction): “To gain knowledge add things every day; to gain wisdom subtract things every day.”
Now as always, there is no single method, not for changing our schedules or our minds, and not for improving our inventions or our political systems. Hopefully more people will come to see adding and subtracting as complementary ways of introducing and understanding change. In the meantime, remember those pocket parks. Because the more people who overlook subtraction, the greater the rewards for those who do not.