Medicine has a proximate and an ultimate register. How does the fever work, and why do we have fevers. Most of psychiatry has been conducted almost entirely in the first. Evolutionary Psychiatry is betting there's a lot of value in exploring the second.

A nice thing about an evolutionary frame is how much it explains that you weren't previously aware needed explaining. Why anxiety and not calm all the time? Why grief at all? Questions you didn't know were questions!

Sleep problems in modern life are often framed as a discipline failure. They're just as often a mismatch failure — a system built for darkness and exhaustion, running on light and stimulants.

The line between 'personality trait' and 'disorder' in most diagnostic manuals is drawn by degree, not kind. Selection rarely produces traits that are all downside - it produces trade -offs, and therefore 'traits' have a range.

A decade of EPSIG: largest lineup yet for the 8th International Evolutionary Psychiatry Symposium - in person at the RCPsych, London, Fri 6 Nov 2026. Luminaries such as Nesse, Le Cunff, Hurst, Spikins, Keedwell, Hurst, Brüne all giving talks! Registration link in tweet below:

We did not evolve to be well. We evolved to leave descendants, and selection was perfectly willing to trade your comfort for their existence. Psychiatry is in some sense, the quintessential study of that trade.

Low mood is not always a fault to be corrected. Sometimes it is information — a signal that the current pursuit is not paying, delivered by a system with no gentler way to say so.

There is a difference between a system that is broken and a system doing exactly what it was built to do under conditions it was never built for. Mistaking the second for the first might have cost patients a great deal.

The reframe people find healing isn't "you're fine." It's "what you're feeling makes sense, given what this system was built to do." Sense-making is half of recovery. Evolution happens to be very good at supplying it.

Half of psychiatry is built on the idea of "normal" - and almost none of it specifies normal for what. Statistically normal? Normal for a hunter-gatherer band? Normal for a system that's overshooting because the threat it's calibrated for no longer exists? These are different sentences.

We keep looking for the lesion. A century of looking for the lesion. The uncomfortable possibility is that for much of what we treat, there is often no lesion: there's a working system meeting a world it was never shaped for.

Mainstream psychiatry asks "how is this brain different from a healthy one." Evolutionary psychiatry asks "what is this brain doing, and what was it built to do." The first question has produced a century of correlations. The second is where the explanations live.

TODAY: Samir Okasha's webinar on "methodological creationism" - a concept that reorganises a whole psychiatric debate. The uncomfortable point: you can do most of modern psychiatry without ever assuming humans evolved — and largely, we do. Worth sitting with. Webinar 25 June, 6pm BST. Link below:

10 years of EPSIG. To mark it, we've booked our biggest lineup yet for the 8th International Evolutionary Psychiatry Symposium — in person at the RCPsych, London, Fri 6 Nov 2026. Nesse, Brüne, Le Cunff, Hurst, Spikins, Keedwell. Registration link below:

Every emotion you'd like to delete was load-bearing for someone who shared your genes. That's why you still have it. The off-switch existed at various points in our history. The lineages that pressed it aren't here to discuss the matter.

Most of psychiatry proceeds as if humans weren't the product of evolution at all. Samir Okasha has a name for this: "methodological creationism." Once you see it, you can't unsee how deep it runs. Join us 25 June, 6pm BST. Link below:

The brain is the most metabolically expensive organ we have. Evolution does not build and maintain expensive things that produce only malfunction. Whatever depression, anxiety, and the rest are, "pure error" is almost certainly not the answer. Expensive systems are "doing something."

We call it "mental illness." We could call it "a brain doing its best in an environment it wasn't designed for." The second framing isn't a kind lie - It's simply more accurate. And it gestures toward completely different interventions.

New Webinar: Samir Okasha's "methodological creationism" begins by asking "how might Psychiatry look differently if we assumed human behaviour was not produced via evolution?" Coming up - 25th of June 6pm BST. Link Below:

Telling someone with depression that their brain chemistry is imbalanced is often disempowering - healing is just a matter of taking a pill and hoping it works. Telling them their system is responding to something real, and we can work out what, gives them somewhere to go.

Status anxiety is rational in a species where status determined access to mates, resources, and allies for two million years. Social media didn't create the wound! But it did remove every natural ceiling on how many people you can measure yourself against.

Disgust evolved to keep us away from pathogens and toxins. Then it got recruited for moral and social judgement — contamination, purity, the "unclean" outsider. Perhaps a lot of human cruelty runs on an emotion that started as food safety. Worth knowing where your moral intuitions come from!

We pathologise the kid who won't sit still, the adult who can't focus, the teenager who sleeps wrong, the griever who grieves too long, the worker who burns out. At some point the sheer number of "disorders" should make you suspect often the problem is the yardstick, or the environment.

What would psychiatry look like if we assumed humans weren't evolved? Samir Okasha's "methodological creationism" thought experiment is one of the most clarifying moves I've seen in this debate. Webinar coming up - 25th of June 6pm BST. Link Below:

Depression as evolved response: withdraw, conserve, reassess, signal need for support. Depression as modern trap: the withdrawal removes you from the very social and physical inputs that would lift it. The response is adaptive. The feedback loop it creates in isolation is not.

There's perhaps a reason every antidepressant trial has a huge placebo response. Belief, hope, ritual, the attention of a caring expert — these are evolved healing inputs. The studies have implicitly been demonstrating the power of the evolutionary-therapeutic relationship for decades.

Of course, some of psychiatry's "treatment-resistant" cases may just be cases where the treatment was aimed at the wrong level. You can't always pharmacologically fix a problem that lives in someone's job, marriage, or total absence of community.

Happening Today, 28 May, 6pm BST: WPA Evolutionary Psychiatry webinar with Iain Campbell (Edinburgh): "An evolutionary perspective on metabolic and circadian dysregulation in bipolar disorder" Register: wpanet.org/section-page...

Why do metabolic and circadian systems break down together in bipolar disorder? Iain Campbell (Edinburgh) brings an evolutionary lens to this question — Thursday 28 May, 6pm BST. Free WPA EP webinar. Register: wpanet.org/section-page...

Reminder: free WPA Evolutionary Psychiatry webinar this Thursday 28 May, 6pm BST. Iain Campbell (Edinburgh) on "An evolutionary perspective on metabolic and circadian dysregulation in bipolar disorder" Register: wpanet.org/section-page...

Every culture in human history has had ritual, music, altered states, and communal meaning-making. Every one. We've largely stripped these from secular modernity and replaced them with..... Certainly less direct 'Ritual.' We then noticed an epidemic of meaninglessness. Chesterton's fence?

The patient who says "I've always been like this" is giving you crucial evolutionary information. Lifelong, stable, pervasive traits that predate any obvious environmental trigger are most likely not disorders in the conventional sense.

The hunter-gatherer workday was roughly 4-6 hours. The rest was rest, socialising, play, story. We built an economy that treats this as laziness and then prescribe medication for the exhaustion - the mismatch is perhaps not subtle.

Schizophrenia has persisted at roughly 1% prevalence across every human population ever studied. That's a Clue. Evolution doesn't maintain costly traits at stable frequencies for no reason. We don't know why yet, but "broken brain" is almost certainly the wrong answer in my view.

There is no such thing as a context-free symptom. Every psychiatric presentation is a response to something, shaped by something, persisting because of something. Evolutionary, non proximate causes of mental disease matter if we want to truly understand them.

The ancestral environment had less powerful algorithms optimising for your continued engagement. Engagement optimisation is not necessarily a bad thing, but it's new. Treat it as new.

Trauma responses make complete sense as evolved reactions to threat, loss, and social rupture. They become problems when the context that triggered them is gone but the system hasn't updated.

What motivates me in regards to Evolutionary Psychiatry is a certain disappointment with current Psychiatry. Psychiatry is the only medical specialty where the diagnostic manual has no clear validated biomarkers, the treatments are uncertain, and with effect sizes that would embarrass other fields.

Spicy Take: the DSM is often merely a cluster of symptoms named with a thesaurus. Describing a cluster of behaviours in Greek doesn't explain it. Naming is not understanding. We've confused the two for fifty years and called it progress.

"Chemical imbalance" was never really a theory. It was a metaphor that escaped its enclosure. Serotonin doesn't cause depression the way a broken leg causes pain. We know this. We kept saying it anyway because the alternative — genuine causal explanation — is hard.

The smoke alarm doesn't malfunction when it goes off during burnt toast. That's the feature. Anxiety that fires too easily in a safe environment is doing exactly what it evolved to do. The context makes the poison - the problem is fitting it to the context, not the alarm system itself.

Psychiatry has thousands of papers on the what of mental disorder. Remarkably few on the "why". Evolution is the only framework that makes "why does this exist at all" a tractable question!

Causal stories matter. Telling someone their anxiety is a calibrated defence system that's overheating - not a sign they're broken - changes what recovery looks like. In fact, one study I, along with others, am publishing indicates this has a measurable effects on outcomes.

The irony of calling ADHD a disorder in the modern environment, which we might describe as one specifically engineered to disfavour sustained attention.

We treat "normal" sadness as clinical depression, "normal" anxiety as disorder, "normal" variation as pathology. The question we never ask: normal for what? For ancestral environments, these responses often made perfect sense.

Modern psychiatry: here is a drug to make the bad feeling stop. Evolutionary psychiatry: what is the bad feeling for.

Despite the prevalence of Anxiety Disorders, Anxiety is not your enemy. It's a system calibrated for an environment that no longer exists. The question isn't how to turn it off. It's what it's trying to tell you - and whether that is appropiate for the situation at hand.

Final reminder: Evolutionary Psychiatry Webinar at 6pm tomorrow. Professor Alfonso Troisi will be presenting the GOAL model — a framework for clinical assessment built on evolutionary principles. 26th March, 6pm GMT. Register here: buff.ly/EbNO5po

Conscientiousness and agreeableness as "slow life history" strategy markers: underappreciated how much personality psychology and life history theory (r/K selection) are saying the same thing in different languages.

Upcoming WPA [World Psychiatric Association] Webinar: Professor Alfonso Troisi (University of Rome) presents the GOAL model — a framework for clinical assessment built on evolutionary principles. Webinar takes place on the, 26th March, 6pm GMT. Register below: buff.ly/EbNO5po