Hand someone a wobbly structure and ask them to make it stable, and watch what they do. Almost everyone adds: a support here, a brace there, more material to prop up the problem. Almost no one removes the single piece causing the wobble. That instinct, multiplied across a working life, is why your calendar is overgrown, and it has a name.
What is subtraction bias?
In 2021, a team led by Gabrielle Adams and Leidy Klotz published a study in Nature showing that people systematically overlook subtractive changes.1 When we set out to improve something, we reach almost automatically for what we can add and fail even to consider what we could take away, even when subtraction is plainly the better answer.
The experiments are clean and a little embarrassing to read, because you recognise yourself in every one. Improve a Lego structure: people add bricks rather than remove the destabilising one. Improve an essay, a recipe, an itinerary, a research summary: people pad rather than prune. Across the studies, participants generated roughly four times as many additive ideas as subtractive ones.2
Why does the mind work this way?
Because of how we search for solutions. When a problem appears, additive options are simply more cognitively accessible. They surface first, and we tend to seize the first workable idea before subtraction ever enters the running.3 It is not that we weigh removing against adding and choose adding. It is that removing never makes it onto the ballot. The bias is a failure of search, not a considered preference, which is both why it is so pervasive and why it is so fixable.
How does it sabotage your week?
Every process at work was shaped by a thousand small forks, and at almost every one, someone reached for addition. A project is late: add a status meeting. A mistake slips through: add an approval step. Communication is patchy: add a weekly report. Each addition felt responsible in the moment. None was ever revisited. The meeting, the approval, the report all became permanent, and the cumulative weight is the bloated week you now inhabit. Your calendar is not a considered design. It is an accumulation of unremoved additions.
This is also why the instinct to “get more efficient” so often makes things worse. Faced with a clogged process, the additive mind reaches for a new tool, a new tracker, a new dashboard, when the cure was to remove a step that should not have been there. AI supercharges the danger, because it makes adding, generating another report, another summary, another layer, nearly free.
What is the cure?
The encouraging finding is that because the bias is a failure to consider subtraction, the fix is simply to make subtraction visible. In the studies, a cue as light as reminding people that they could add or remove more than doubled the rate of subtractive solutions.2 The option was always there. People just needed pointing at it.
So install the cue as a habit. Before improving anything, before adding a tool, a step, a meeting, a check, ask the question your mind keeps skipping: what could I remove here? Make “what should we stop doing?” as routine a question as “what should we start doing?” Run it over your recurring commitments, your processes, your obligations.
You will be startled how often the best improvement is a deletion, and how rarely you would have reached for it unprompted. Less is genuinely more, but only if you remember that less is an option. Your brain will not remind you. You have to remind it.
Frequently asked questions
What is subtraction bias?
Subtraction bias is the systematic tendency to solve problems by adding things rather than removing them, even when removing is the better solution. A 2021 Nature study found people overwhelmingly reach for additive changes and overlook subtractive ones.
Why do we overlook removing things?
Because additive solutions come to mind first and we accept them before subtractive ones are even considered. The bias is a failure of search, not of preference, so simply being reminded that removal is an option largely corrects it.
How do you counteract subtraction bias?
Cue subtraction explicitly. Before improving anything, ask what could be removed, not just what could be added. In studies, a prompt as light as you may add or remove more than doubled subtractive solutions.
About the author
Tom Goodwin is the author of Don’t Work Harder, a book about taking the time AI gives back as time rather than more work. He is a co-founder of GAMEPLAN and writes on productivity, technology, and the economics of the working week.
Footnotes
Footnotes
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Gabrielle S. Adams, Benjamin A. Converse, Andrew H. Hales, and Leidy E. Klotz, “People Systematically Overlook Subtractive Changes,” Nature 592 (2021): 258 to 261. ↩
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Adams et al. (2021) and replications: participants generated far more additive than subtractive ideas, and explicitly cueing subtraction more than doubled the rate of subtractive solutions. Treat as a strong, replicated tendency rather than an absolute law. ↩ ↩2
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Adams et al. (2021) attribute the bias partly to heuristic memory search: additive solutions are more accessible and are accepted before subtractive ones are considered. ↩