The Disevolution Test
When you are handed a fix, ask whether it treats the cause or quietly makes you dependent on treating the symptom.
- Difficulty
- Easy
- Time to result
- ~ongoing to results
- Steps
- 5
- Confidence
- 80%
Lieberman defines a mismatch disease as one that is more common or more severe because our bodies are inadequately adapted to modern environments, and disevolution as what happens when we treat the symptoms of a mismatch disease rather than their causes. The test is a decision lens: whenever a modern intervention is offered, separate what it relieves from what it fixes, and check whether accepting it makes the underlying weakness permanent. Plantar fasciitis and orthotic insoles are his worked example - the insole genuinely relieves, but leaves the weak foot weak, so the dependency lasts for life. The lens generalises well beyond health to any comfort-purchasing decision where the short-term benefit is real and the long-term cost is deferred and invisible.
Origin
The concepts come out of Lieberman's work in evolutionary medicine - applying evolutionary theory and data to health and disease - which he entered through the back door after starting his career on skulls and human evolution.
Core principles
- 01A mismatch disease is one made more common or more severe by an environment our bodies are not adapted to.
- 02Disevolution is treating the symptoms of a mismatch disease rather than their causes.
- 03Symptom relief is legitimate; unexamined symptom relief is a trap.
- 04Comfort is not evidence of benefit - we routinely pay extra for it and rarely ask what it costs.
- 05We overweight the short-term benefit against the long-term cost; the technical name is hyperbolic discounting.
- 06Systems are built around treatment because that is where the money is - prevention is nobody's specialty.
How to run it
- 1
Ask the diagnostic question: where did I go wrong?
When something unnatural is prescribed to you, treat it as information about an upstream failure rather than as the answer. Bartlett's instinct - to ask why he needed insoles at 30 when his ancestors did not - is the correct opening move.
Watch out The question is not a rejection of the treatment. It is a separate line of enquiry that runs alongside it.
- 2
Separate what it relieves from what it fixes
State explicitly which symptom the intervention removes and which underlying cause, if any, it addresses. The insole stops the arch collapsing so the fascia is stretched less; it does nothing to the weak foot muscles that let the arch collapse.
Pro tip If the honest answer to 'what does this fix' is nothing, you have identified a disevolution candidate.
- 3
Check whether the fix creates dependency
Ask what happens if you stop using it in a year. Lieberman likens the insole to putting the foot in a cast: for the rest of your life you keep needing them unless you strengthen your feet. Dependency is the signature of disevolution.
Watch out Dependency often reads as success, because the symptom stays away for as long as you keep paying for the intervention.
- 4
Take the relief and run the cause fix in parallel
Use the symptomatic treatment - pain is no fun, so wear the insoles - while simultaneously working on the cause. Lieberman's expectation is that with the cause addressed, the condition disappears and does not come back.
Pro tip Running both in parallel avoids the false choice between suffering and dependency that makes people abandon the cause fix.
- 5
Apply the same lens to comfort purchases generally
Extend the test beyond medicine to any choice where comfort is being bought: cushioned shoes, elevators over stairs, high-glycaemic convenience food. Ask in each case what capacity you are outsourcing and what the deferred bill looks like.
Pro tip The rule of thumb Lieberman keeps returning to is that comfort sells, and comfort being nice is not evidence that comfort is good for you.
Watch out This is a lens, not an ideology. Lieberman explicitly rejects banning elevators or forcing dietary choices, and supports accessibility needs without qualification.
In the wild
Bartlett's podiatrist scanned his foot, told him his arch was too flat, and prescribed insoles for every shoe. Lieberman classified plantar fasciitis as a mismatch disease and identified the cause as a weak foot produced by stiff-soled, arch-supported shoes doing the muscles' work. The insole is real relief - it prevents the arch collapsing so far, so the fascia is stressed less - but leaves the weakness untouched, which is why he calls the practitioners a bit like drug pushers and the pattern disevolution.
→ The prescription is to wear the insoles for pain while deliberately strengthening the foot, so the dependency ends rather than becoming lifelong.
Flying from Denver to Boston, Lieberman watched everyone queue for the escalator beside a completely free, not especially large staircase. He ran up the stairs, because he does not allow himself the escalator unless he has to. His reading of the queue is that nothing is wrong with those people - taking it easy when you can is an instinct, and modern environments let everyone act on it constantly.
→ It illustrates the comfort trade at population scale: a convenience that is individually rational each time and collectively costly over a lifetime.
Lieberman points out that the United States spends around 3% of its medical budget on prevention, while roughly 75% of the time a patient walks into a doctor's office the disease is, by the CDC's classification, preventable. Medical schools do not seriously teach nutrition or exercise, schools of public health are marginalised, and there is no such field as preventive orthodontics, preventive optometry or preventive orthopedics.
→ Lieberman calls it a completely backward, stupid system - disevolution institutionalised at the level of an entire healthcare economy.
Common mistakes
Refusing the symptomatic treatment on principle
Lieberman is explicit that there is nothing wrong with treating symptoms and that pain is no fun. Rejecting relief in pursuit of purity means you suffer and, in the case of an inflamed and poorly vascularised tissue, may prevent the healing that the cause fix depends on.
Assuming comfort indicates benefit
Comfortable shoes are comfortable because your muscles are doing less; a comfortable chair and the lift are comfortable for the same class of reason. Comfort is a sales proposition, and Lieberman's repeated question is since when is comfort necessarily better for you.
Waiting for the system to prioritise the cause
With 3% of the medical budget on prevention and no preventive specialties, the incentive structure reliably surfaces the symptom fix and not the cause fix. If you do not run the test yourself, nobody in the chain is being paid to run it for you.
Is it for you?
Best for
Anyone evaluating a prescribed device, supplement or convenience purchase, and decision-makers who need a fast way to distinguish a patch from a fix.
Not ideal for
Acute or emergency situations where symptom control is the whole objective, and conditions with a genuine structural cause that no amount of strengthening will address.
From the transcript
“plantar fasciitis is what I would call a mismatch disease, right? A disease that's more common or more severe because our bodies are inadequately adapted…”
“that's a typical example of what I call disevolution. It's what what happens when you treat the symptoms of a mismatch disease rather than their…”
“there's nothing wrong with those, you know, treating the symptoms. I mean, pain is no fun. So, wear the insoles, right?”
“But since when is comfort necessarily better for you, right?”
“we often value the short-term benefit over the long-term cost, right? Um that's, you know, hyperbolic discounting is the technical term for that.”
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