Hope you SF rats are watching Steph Curry do his magic from outside tonight. Hey Steph, put that mouth guard back in your mouth!

Oh, from that distance it should be 4 pointer!

Expand full comment

I've seen a theory that mass shooters are likely to not have grown up with a father in the house. I don't find this plausible, but I suppose it should be checked.

Expand full comment

Does anyone have any advice for managing ADHD? I don’t like the side effects of adderall, I don’t that Modafinil more than once a week because of tolerance. I’m also a nicotine user, which helped at the beginning but I’m kicking the habit now.

I would really love a non-chemical alternative, but nothing has worked for me. I’m kind of half hoping that someone here will propose some crazy underground therapy that will help (cbt-based therapy for adhd did little for me)

Expand full comment
Jun 1, 2022·edited Jun 1, 2022

I recently switched from chrome browser to vivaldi. I'm liking it quite a bit so far! I don't know a lot about the development behind such things, but I'm loving how much control I have over it. It's got the ad blocking of firefox, the privacy protection of duckduckgo, and the tab stacking and backend of chrome! I highly recommend it!

Expand full comment

I feel like both the red and blue tribes have been trying to gaslight me on covid. Do we have enough reliable data now to push back?

Expand full comment

According to random news I see online, Russia has already lost 30 000 soldiers in Ukraine. But also, they have transferred over 200 000 Ukrainian children to Russia, to be reeducated and raised as patriotic Russian citizens.

This made me think: what if the true reason for this war has always been solving the demographic curve of Russia? Conquering the entire Ukraine would have worked too, but this also accomplishes the strategic goal.

Expand full comment

Hi Scott. Do you know what is up with Silexan? The link in your original essay no longer goes to anything.

I had ordered some to give it a try, and well at least there was a placebo effect so I tried reordering it and received something else, called Calm24 from a company called Natura instead.

The packaging says each caplet contains 500mg of ‘cold macerated lavender oil’.

It seems like Amazon might still have the original product with a pack of two 30 count soft gels for 42 bucks so it would seem there has been a jump from 12 to 21 dollars for a two week supply.

I’m not going into lavender withdrawal or anything just a bit confused.

Edit: A bit more annoyance. I tried to set up a return of the stuff I just got from Natura and ran into ‘this product can’t be returned’

Further Edit:

This is meant more of a heads up than a serious question. Of course there is no way for Scott to know what is happening here.

Expand full comment


Using somewhat old astronomical data to find asteroids and their orbits. A lot of computation in the cloud.

Expand full comment
May 31, 2022·edited May 31, 2022

Is the Axial Age an actual thing that happened, or is it mere cherry picking of events? And in case it's real, what may have case such a temporal clustering of philosophical-religious innovation?

I think the silk road was already a thing in 500 BC, so maybe ideas were going back and forward with commerce? Or maybe this was a period of heightened conflicts at the steppe boundary which has catalyzed empire formation?

Has scott ever written on the subject?

Expand full comment


Using AI to improve tennis play.

Expand full comment

Has Scott ever written an update opinion on Mark Cuban's Cost Plus Drugs effort? Is it providing a lot of utility? Is he missing key drugs?

Expand full comment
May 31, 2022·edited May 31, 2022

Hey Scott, check out this Language Log post if you haven't seen it already. It's about the origins of the name Moloch and there is surely some kabbalistic fun to be had: https://languagelog.ldc.upenn.edu/nll/?p=54844#more-54844

Expand full comment

Anyone else learning to code as an adult whilst working full-time in an unrelated STEM field?

What resources, tips, learning habits, etc. would you recommend?

I've enrolled in a 10-week Python course - partly for the sake of learning itself, and partly for the ability to spin up some basic code to run alongside numerical modelling and CAD programs I used for work. I'm sticking to the script and using Anaconda / Spyder / Jupyter.

Expand full comment
May 30, 2022·edited May 30, 2022

By any chance can anyone point me to studies on what the language center(s) of the human brain are doing during dreaming? Google Scholar isn't turning up anything about my specific question.

Some of the popular science articles — which may actually be popular pseudoscience articles — say that the language centers of our brains are mostly off-line during dreaming and that we're not really hearing language, rather we just have the illusion of hearing language in our dreams. Deirdre Barrett PhD from Havard seems to be the designated expert that the popular science press goes to for dream questions, but I can't find any publications by Barrett regarding language in dreams. But she seems to be the source of the claim that our language centers offline during dreams, and that's why we aren't supposed to be able to read in our dreams (she does qualify it in a quote by saying "most people" can't read in their dreams).

The reason I ask is that I had an interesting dream the other night. I was playing ngau-ngau (which is a popular gambling card game in Hong Kong), and all the people sitting around the table were speaking Cantonese. I could understand part of their conversation—especially numbers and swear words—but a lot of their conversation was opaque to me. This wasn't surprising to me, because when I lived in HK, I developed rudimentary conversational skills in Cantonese, but there were frequently words I couldn't understand and I would have to ask what they meant.

Upon waking, though, what struck me about this dream was that if I were *not* really "hearing" language in my dream, why couldn't I either (a) understand all of their conversation, or (b) understood none of their conversation? Full disclosure, I don't know how to play ngau-ngau either, but I wasn't really playing—rather I was just sitting at the table with the players as they smoked, joked, laughed, and swore (and spat).

As for Barrett's claim that I shouldn't be able to read in dreams, after a lifetime of active dreaming, I have been able to "teach" myself to read in dreams. But I'm only reading at about a 1st Grade level right now. "See Spot Dream. Dream, Spot, dream!" I can't decode complex words or phrases that show up on printed material in my dreams. So no reading the latest articles in Nature Dreaming for me.

Expand full comment
May 30, 2022·edited May 30, 2022

Scott's recent article on the Hearing Voices Movement ( https://astralcodexten.substack.com/p/in-partial-grudging-defense-of-the ) convinced me to post a wall of text I had previously drafted with regard to involuntary commitment to psychiatry.

Involuntary commitment (and how to avoid it)

(Trigger warnings: psychiatry, long text, Germany, vitriol, badly cascaded section titles, shortages of charity towards the wardens).

In my (limited, Germany-centric, 3rd person) experience, involuntary commitment into clinical psychiatry is best seen as a Moloch-powered soul-crushing machine. While not all encounters with psychiatric clinics end badly, and some might in fact be beneficial, the possibility of landing on the conveyor belt running straight towards the soul mill always exist.

= TL;DR =

Involuntary commitment is a very real threat to any patient of clinical psychiatry, and can make your life worse for a very long time. Never go willingly into any unit with a locked door. They will lie freely, so lie to them in turn if you have any symptoms of psychosis. Do not expected to be treated like an adult(ish) human. For Germany, have a living will naming a trustworthy, rabidly anti-psychiatric friend as a guardian. For the hearing, get a fighter lawyer. If any of your jailors break the law, press criminal charges.

= How psych ward is different from other wards =

If you are naive like me, you might think that a psychiatric ward is like a bone ward, only it is for treating psychic illnesses instead of fractures. Of course, you read/saw "one flew over the cookoo nest", but that was the dark ages. Today, unthinkable. As the late Danton would say: "Ils n’oseront pas!" They would not dare. Yes, there is an anti-psychiatric movement, but then again, there are tons of movements devoid of any substance, why should they be any different?

If you are admitted to a cancer ward with a life expectancy of less than a year without treatment, and form the opinion that you do not want to be treated, you will generally be free to leave against medical advise after signing some forms. Your personal autonomy trumps any amount of outcome difference, end of story.

Contrast that to psychiatry. The moment you walk through the door, your autonomy is in jeopardy. After all, any objection you might have to the proscribed treatment could well be a symptom of your mental illness instead of your will.

If it was the other way round, with the psychiatrists respecting patient autonomy and the oncologists routinely violating it, that would be bad enough, but workable. Human rights issues aside, treating cancers should well work without the patients compliance. Biopsies and CT/MRI images could still be taken (perhaps using a sedative), surgeries would be unaffected, patients might have to be prevented from removing chemotherapy IVs, but otherwise, treatment efficiency should not suffer too much.

They way it is, instead, is horrible. Most psychic illnesses can not be diagnosed based on physical findings, so one is stuck observing the patient for diagnosis instead. Some symptoms will be deducible without any patient cooperation whatsoever, but for most, one will have to rely on the patient to self-report them. In fact, I would be hard pressed to name a field more reliant on patient cooperation for diagnosis.

= How the spectre of involuntary commitment poisons doctor patient relationships =

In a normal doctor patient relationship, this would be no issue. Opioid addictions aside, a patient generally has no incentive to lie to their orthopedist about the presence or absence of joint pain. Their goals align.

A psychiatrist (or psychologist) working within a system permitting involuntary commitment, however, is never just a physician or therapist. They also occupy the position of a kind of attorney general who will have to decide on whether the case warrants bringing in a judge to lock the patient up. If that happens (and the judge agrees -- which he generally will, trusting the expert opinion of the psychiatrist, as there are no physical criteria fit to be used as evidence), our psychiatrist will wear the hat of the prison warden as well when working in a "secure unit" (a very newspeak term itself, as even the short term security provided to the de facto prisoners of mental institutions is very debatable).

The system will only work as long as the patient is unaware of the stakes or (rightly or wrongly) convinced that their symptoms do not warrant commitment.

(continued below, this ended up being part 1 out of 3).

Expand full comment

Maybe someone can tell me whether this makes sense, or can even do the math:

It occurred to me there is a population-based factor in the observation that technological advance was (before about 1970) exponential even after being adjusted for population.

People have approached that comparison with the unspoken assumption that the way to do it looks something like this:

population doubling time =~ 40 years

tech doubling time =~ 20 years

therefore technology's exponential increase is too high to be accounted for by population

therefore tech has accelerating returns

This comparison assumes that the technology output from N people at time t, tech(N,t), is simply N*tech(1,t), so that tech advances are proportional to population.  But this overlooks the fact that tech(N,t) is in reality not a function, but a probability density function (pdf).

My first instinct was to instead test whether tech(N,t) can be written just as a function of N, tech(N), under the supposition that that would mean tech production doesn't depend on pre-existing tech, and so tech has no accelerating returns. This turns out not to work as a test, for tricky semantic reasons I don't want to get into. For now I'm going to write tech(N,t) as tech(N), even though this is not strictly correct.

We observe only a sampling of tech(N), and computing the average of that sample will never give the expected value of tech(N), because it's very skewed.  The pdf tech(1) is even more skewed; so we can't compare E(tech(N)) to E(tech(1)) just from observed data without a theoretical adjustment for the observations we never observe.  Even if the expected value E(tech(N)) = N * E(tech(1), it would still be the case that we would almost certainly always OBSERVE tech(N) > N * tech(1).

The probability distribution for tech output from 1 person is almost certainly given by a power law of the form p(x) = cx^(-a), a > 1.  That would imply that the pdf for tech(1) has much more of its mass in, say, the top 1% of possible observations, than does tech(20), because of black swans.  If a < 3, Variance(tech(N)) is infinite, so most of its mass is in parts of the PDF that we never see.  If a < 2, the expected value E(tech(N)) is also infinite, which we can interpret as meaning that *all* of its mass is concentrated in parts of the distribution that we never see.

In other words, E(tech(N)) = N * E(tech(1)) doesn't imply that median(tech(N)) = N*median(tech(1)), and so we can't just say that the fact that tech doubling time is less than the population doubling time implies that the output of individuals isn't constant.  We have to find out how much of the observed difference can be attributed to the greater skewedness of the probability distribution function (pdf) p(tech(1,t)).

median(tech(N,t)) would still grow faster than N * median(tech(1,t)).  But I haven't done the math to figure out how much faster.  It may help to know that median(p(x)) = c*2^(1-a).

Going back to the original comparison of population and tech doubling times, we should expect that we'll observe a faster tech doubling time *even if there are no increasing returns to technology*.  This is because if we measure the sum of the importances of all tech advances per decade, these measurements won't approximate the expected sum, but will be better approximated as proportional to the significance of the most-significant single advance we happen to snag in our sample.  And this significance will (I think) increase exponentially with population.

Expand full comment

Re Alito et. al. overturning Roe v. Wade

What do people here think of a referendum (either national or state-by-state)? If voters were asked:

"What is the maximum number of weeks into pregnancy that an elective abortion should be allowed?"

then sorting the results and picking the median value gives a length such that half the electorate

thinks it is too long (too lenient) and half the electorate thinks it is too short (too stringent).

It has the advantage that:

It is a direct choice by the voters.

It is a reasonably concrete choice, unlike e.g. picking coefficients in a tax code polynomial.

It has reasonably simple consequences. At most, educating voters about the timeline is reasonably straightforward

and less controversial than the overall issue. ("Typical first heartbeat at N weeks. Typical first neuron at M weeks. Typical viability at...")

Aggregating a one-parameter choice like this with monotonic consequences doesn't get into voting paradoxes.

My _personal_ preference is to allow abortion at any point. Roe v. Wade (which is slightly more restrictive than that) struck me as a reasonable _policy_ - but, unfortunately, Alito is correct that neither "privacy" nor "abortion" nor "bodily autonomy" is in the text of the constitution. I, personally, would prefer to add constitutional amendments specifically protecting all three, but that isn't going to happen.

Expand full comment

A Girardian reading of Stephen Spielberg’s JAWS.

While I was an undergraduate at Johns Hopkins while Girard was on the faculty and eventually came to read Violence and the Sacred when the English translation came out (1977), I have never been a Girardian. But I had been in the orbit of Richard Macksey when I was at Hopkins, and Macksey had worked closely with Girard in the (in)famous structuralism conference that took place in the Fall of 1966. Consequently I had heard Girard lecture on mimetic desire and the logic of sacrifice and it stuck with me.

A couple of years or so ago I decided to watch Stephen Spielberg’s Jaws (1975), which I had not seen when it first came out. I thought it was a pretty decent film and that was then. Then, for some reason or another – boredom, who knows? – I decided to watch it again, and again. I took notes. I watched Jaws 2, which was not directed by Spielberg. It wasn’t nearly so good either, too diffuse and it lacked a character comparable to Quint in the original. I just barely made it through Jaws 3 and simply gave up on Jaws 4 at about 40 minutes in.

So, I asked myself, why is the original so much better than the sequels? As soon as I’d asked the question, that pesky light-bulb over my head started blinking like mad: sacrifice! mimetic desire! Girard!

And so I worked out a Girardian reading of the film: Shark City Sacrifice: A Girardian reading of Steven Spielberg’s Jaws. I figure there must be someone around here who'd be interested in such an animal, so here's the link, https://3quarksdaily.com/3quarksdaily/2022/02/shark-city-sacrifice-a-girardian-reading-of-steven-spielbergs-jaws.html

Expand full comment

A few months ago, our project won an ACX grant to try to pursue a potentially far-reaching idea of spellchecking genomes with genetic editing. We are looking for a genetic editing expert to help in an advisory capacity, or potentially even join the core team.

Please reach out to us at at spellcheckhealth@icloud.com if this sounds interest to you - thanks!

Expand full comment

This summer program is held in America too and called Sparc. They only select 30 srudents a year. My son applied in 11th grade. Didn't get in, but he thoroughly enjoyed answering their application questions - lots of interesting puzzles, I think, he said. None of the college essay type stuff like "If you were a tree which tree would you be?" :)

Expand full comment

What's the EA line on blood donations? I'm particularly interested in platelets since that's what the Red Cross has been hounding me about lately, but it's a bit more burdensome than normal donations so I'm curious how the benefits compare.

Expand full comment
May 30, 2022·edited May 30, 2022

For anyone interested, I've just posted my non-finalist book review contest entry, on David Foster Wallace's famous cruise essay: https://whimsi.substack.com/p/book-review-a-supposedly-fun-thing?s=w

Disappointed not to have been a finalist this year after my surprise people's choice awards victory in 2021, but I think ACX readers are just generally more interested in a quasi-political memoir like Orwell's Down and Out then in a surreal, navel-gazing essay on luxury cruising, so I can't say I'm exactly surprised. That said I think the DFW Cruise Essay is of much greater immediate import to most readers of ACX, given that most of us are middle-class westerners with far too much time on our hands.

Expand full comment

I’m working on studying up on AI and AI alignment and I’m looking for book recommendations. I just finished Superintelligence and Human Compatible. What should I tackle next?

Expand full comment

Okay, so there is the subreddit, Discord, bulletin board and of course the open threads like this one. Can you tell me, what of those you use for what? How are they/ is your focus there different or similar?

Expand full comment

I was wondering, how well we know Autism to say it is not, as a diagnosis category, the 21st century version of hysteria?

I was at a family function with a distant cousin who is a nonverbal autist and I realized he has quite different symptoms and traits than the usual high-functional cases we see. Is there a common link that connects the lighter to the more severe cases, or are we perhaps putting different diseases together into one giant diagnosis pile?

Expand full comment

Not my project, but I found a guy doing microgrants for chaotic projects. It’s at https://www.pandemonium.capital/ if anyone is interested, I think it’s a fun idea

Expand full comment

In the spirit of doing low status things with high potential, I am working on a site to allow commissioning of fringe erotica and am looking to hire a second web developer.

The idea is to build a place where people with niche interests can post bounties for specific stories. In my time moonlighting as an erotic author, I've noticed a lack of good sites to do freelance erotic writing work. I think the reason for this is that most people think porn is icky, so despite there being a huge market for extremely niche content, the platforms currently available are pretty abysmal. This is our opportunity.

We're currently in beta and can pay a junior-level wage, with senior-level equity. If you're a web developer who wants to join a fully remote startup, please reach out at https://www.outfoxstories.com/blog/careers/

As with my other startups, I began this project with the goal of generating wealth to put towards alignment research.

Expand full comment

Everyone says the next crypto winter is here (and I agree). If you’re a person working on a blockchain project, what’s your plan for the immediate future?

Expand full comment

There's this chart on left-handedness over time, showing that after left-handedness became accepted in the population, the rates grew until it stabilized at approximately 12% (https://pbs.twimg.com/media/E5KIFQ9VcAIjrP5?format=png&name=4096x4096)

Previously, I assumed we had already reached the steady equilibrium rate for LGBT identification (at approx 10%), but seems according to this Gallup poll, LGBT identification for Gen Zers is twice the rate as for millennials (at 21.8%). https://content.gallup.com/origin/gallupinc/GallupSpaces/Production/Cms/POLL/nbzubdv9nkelneda6cfb6q.png

I'm curious to hear the community's opinion on this; in 10-20 years (in Western countries), what do you forecast the percentage of people who self-identify as LGBT be? Is the real number above 20% as more people feel comfortable self-identifying, or is this recent polling data aberration and it will go back down to closer to 10%.

Expand full comment

I'm setting up a new VC fund in Prospera that focuses on "stranded technologies" that are hard to realise somewhere else: https://infinitafund.com/

If you're working on a startup in fintech, healthcare, edtech or proptech, check out the conferences I'm organising this year.

To give you a few examples:

- We're building a tokenised real estate marketplace for new construction, because well... we can get building permits there

- We can do human trials there for gene therapies to collect FDA-auditable data, to expedite the approval process

- If you want to set up a new bank or insurance, or anything really ... you don't need to convince the government to give you a license, you need to convince a liability insurance

Expand full comment

I wrote about my predictions for Britain in the 2050s (excitingly Tyler Cowen shared it on Marginal Rev) https://medium.com/@bobert93/a-very-british-2050s-1c75782e790b . Feedback welcome

Expand full comment

Advice needed:

My mother inherited some exurban land in a town she has never lived in (USA). It's in a spot with a nice view and is clearly destined to be subdivided for 3 or 4 houses. But neighboring homeowners don't want their views blocked and were politically connected enough to block her previous application for subdivision 15 years ago. She hasn't done anything since except pay taxes on it - she has an ugh field about dealing with the issue but also refuses to sell it for cheap just to get rid of it.

How can I help her sell it? I figured it's probably an issue for a knowledgeable local agent, but how do I find one capable of handling it well? Am I looking for a real estate agent, a developer, some kind of specialist lawyer, or something else?

Thanks for any tips!

Expand full comment

An essay wondering if we've hit a tipping point in complexity:


Expand full comment

I recently broke up with my ex-girlfriend, who has BPD. She was doing a bit better when she was me, but has fallen back into pretty deep depression in the past weeks. This morning she called me completely down, saying she knows for sure she can't handle live alone. Her intense therapy starts this september, but she hinted at not being able to survive for that long. She has had suicidal ideation before, never an attempt.

Now she asked if I could meet up this week. I have no idea what to do. I don't want to be cold to her and want to be supportive and kind, but I also don't want a sort of continued dependency. Anyone with a background in psychology/psychiatry or similar experiences who could give me some advice?

Expand full comment

I used to be an avid follower of Scott's blogs 1-1.5 years ago, randomly got reminded of this blog again today and was wondering what happened that led to me not following the blog for more than a year slowly. I glanced at the posts, and found a lot less of them to be interesting to me. I wonder if interests changed for me or Scott started writing about different things.

Expand full comment
May 30, 2022·edited May 30, 2022

With the recent news about the infant formula shortage, I wanted to highlight a little-known issue: soy infant formula contains high levels of phyto-estrogens which may disrupt reproductive development. If you're worried about BPA, genestein is an even greater endocrine disruptor. You can read more here: https://denovo.substack.com/p/risks-of-soy-infant-formula

(I should note, eating soy is fine unless you're an infant and get 100% of your diet from it)

Expand full comment

This might delight Scott and anyone who appreciates his answer to Job: Stephen Wolfram's concept of the Ruliad https://writings.stephenwolfram.com/2021/11/the-concept-of-the-ruliad/ is roughly the same idea, but mathematical not theological. It is a kind of hypergraph of all possible states and all possible transitions between all states from all possible starting conditions. "The full ruliad involves taking the infinite limits of all possible rules, all possible initial conditions and all possible steps." Wolfram claims that for some fundamental mathematical reason this has to exist! But we only see the tiny part of it that we happen to inhabit.

Expand full comment
May 30, 2022·edited May 30, 2022

Given a set of desired standards, what's the most optimal way to find a girlfriend?

Expand full comment

Wolfram is still being invited to give speeches? Geez, that guy practically defines the category of underachiever. Rarely has someone of such young promise ultimately achieved so little, unless it be Harlan Ellison as a writer.

Expand full comment
May 30, 2022·edited May 30, 2022

I lost all respect for 80,000 hours when one of their main examples of their philosophy in action is some crypto millionaire who donated to the Biden campaign. No, really.

So, not somebody who put in the work to create a socially beneficial career, and not somebody who has used the proceeds of their "career" to donate to effective altruistic causes (unless I'm very much mistaken, in which case I have lost all respect for EA as well).

Expand full comment

I'm looking into seeing a therapist for the first time ever. I found a guy who's close and takes my insurance. Seems altogether like a good fit for me but he's Jewish (former rabbi) and I'm an Atheist (raised Jewish). I'm worried that I'll present a problem like "I feel like my life is meaningless" and the conversation will drift towards "have you tried believing in god?" like it always does when I talk to theists. Is this a valid concern to have or am I being dumb and not respecting his professional credentials?

Expand full comment

Did anyone give an answer to the request at the end of Motivated Reasoning As Mis-applied Reinforcement Learning post (https://astralcodexten.substack.com/p/motivated-reasoning-as-mis-applied?s=r):

> If there’s other research on which parts of the brain are / aren’t reinforceable, or how to run your thoughts on one kind of architecture vs. the other, please let me know.


Expand full comment

Why do women have breasts?

I would like to launch a (brand new?) theory about why human females develop breasts at puberty, while other primates only have visibly enlarged breasts when they breastfeed. I have written it down on my blog here:


A summary of the theory:

- Our early ancestors probably were rather similar to the chimpanzee and had a mating system rather similar to that of the chimpanzee.

- Chimpanzee females go in and out of estrus, which is highly visible as swollen, red genitalia. Our ancestors probably had detectable periods of estrus too, like most animals.

- Chimpanzee males hold a strong preference for mating with females who are already mothers. Being an ape mother is difficult and first-time mothers often fail, so chimpanzee males prefer more experienced females.

- Except for the fact that chimpanzee males prefer somewhat older females, they aren't especially selective. Being promiscuous animals they want most females and they compete ferociously for the alpha position in order to get them.

- Humans obviously took another path. Presumably that happened gradually among our ancestors, so males started to invest in females and their children little by little, while females still did most of the work.

- When our male ancestors started to invest in their children, it was important for them to get as much value as possible for their investment. They needed to carefully select the females who could bring them children with the least investment possible. So they searched for females who seemed to be as self-reliant as possible. When more stable unions between males and females developed, males also benefited from unions with females who were capable of giving birth frequently.

- Among chimpanzees, birth spacing varies greatly among individuals and depends at least in part on the female's nutritional status. After having a child, chimpanzee mothers only return to estrus when they are able to reach a positive energy balance after the strains of pregnancy and lactation.

- Unusually well-nourished chimpanzee mothers return to estrus when their child is less than two years old. By that time they still have milk-filled breasts, as chimpanzees don't wean their children totally until the age of 4 or 5 years. Less well-nourished chimpanzee mothers don't return to estrus before they finish breastfeeding, because they can't afford to be pregnant and breastfeed simultaneously. So they only mate when they have flat, milk-free breasts.

- That way, estrus combined with big breasts showed that a female was both able to feed herself rather well and that she could give birth frequently. In the pool of estrus females, males had every reason to choose the big-breasted ones.

- Males supported estrus females who had big breasts more than flat-chested females. That gave females who happened to store fat in their breasts an advantage, because males couldn't easily spot the difference between breasts big from lactation and breasts big from fat storage.

- In response to females' development of fat-breasts, males needed to look for the even bigger fat-and-milk breasts. In response to which females developed even bigger fat-breasts beyond the point of impracticality.

- This happened a very long time ago, but there hasn't been enough evolutionary pressure to undo the process completely since. A mutation that among other things contributes to smaller breasts has increased in frequency independently among East Asians and Native Americans during the last 35 000 years. https://en.wikipedia.org/wiki/Ectodysplasin_A_receptor This suggests that there could indeed have been an evolutionary pressure to reduce breast size after more recent human mating systems made breast-size reproductively irrelevant.

Expand full comment
Comment deleted
Expand full comment
deletedJun 1, 2022·edited Jun 1, 2022
Comment deleted
Expand full comment
Comment deleted
Expand full comment
Comment deleted
Expand full comment
Comment deleted
Expand full comment
Comment deleted
Expand full comment