This is, of course, exactly the kind of result that you would expect to get given the way that heritability is defined. When you make environment more uniform in terms of quality, you drive up the heritability, and vice versa.

The strength of the effect is still interesting, though.

Is the total amount of variation the same in different populations? How does the magnitude of the variation contributed by genetics compare?

(That is to say, one percentage may be very different from another percentage.)

I put a HBD chick into play.

Would you recommend the novel in general?

1) Official paperwork, especially if it's the sort where a trivial error can be a major hassle, like tax forms. I have some fairly serious Ugh Fields around the latter.

2) I obsess over previous mistakes, even ones that were made months or years ago. I even obsess over hypothetical mistakes, where I could have screwed something up if I'd been a trifle less lucky or if my synapses had fired a little differently. The mental monologue in the first case runs something like goddamnit, I'm supposed to be better than that. In the second case it's more of an abject horror at what Could Have Happened.

Upvote for meetups!

1) Job searching. It forces you to really size yourself up and compare yourself to everyone around you.

2) I really like your example. My own: feeling pressured to hang out with certain friends (because they'll feel neglected). Rather than realize that friends that guilt you into seeing them need to be see LESS, my brain just makes me feel bad.

1) I find that interacting with other people face-to-face is mentally exhausting for me. A few hours or so of prolonged exposure is not so bad, but more than that and I have to exert noticeable effort to not be snappish and crabby with people.

2) I suffer from an unreasonable need to sit with my back to a wall, or some other solid structure, even within my own home.

I distinctly remember telling a friend when I was 24 that I didn't think I would have children and didn't particularly want any. She laughed at me and told me I couldn't fight biology. I sneeringly informed her that I was master of my own existence and wouldn't be pushed around by evolution.

By age 27 I had a child, which, by that time, I wanted very much.

I would say the stability of your preferences depends very much on your reasons for not wanting children. I find that abstract reasons such as "the world is overpopulated and I don't want to contribute to that" or "my professional life would suffer for a few years" are very easily shrugged off, when it comes down to it. By far the most important factor is how your spouse and/or romantic partner feels about the issue, assuming you have or want one of those. So if you're really serious, be sure to choose a mate who also doesn't want kids, and be sure that they are just as firm in their convictions as you are.

Is there any information available about the latest age at which people are likely to change from not wanting children to wanting them?

But I'm worried that if I plan not to have children, I'll change my mind later.

Why is this a problem? Freedom of choice is a good thing to have. If you really want to commit future-you to the choices that now-you wants to make, there is a variety of surgical procedures that are moderately hard to impossible to reverse. But again, why do you want to give up future choice?

How will I know when my preferences are stable enough to plan around?

Future is uncertain. Your preferences will never be cast in stone and that's a good thing. Whatever you plans are, they should take into account the fact that things will (not may) change.

My suggestion: find people who have young children right now, or are about to. Volunteer to help them out if they ever need any assistance, and see if you can observe what the daily routine with children is actually like. (If you had younger siblings, you may already know a bit of this, but seeing it from the view of someone who's actually responsible for them is going to be quite different.) If you find good reasons for why you'd absolutely hate the experience, then that's some evidence for your preferences not changing (though having your own child is quite different from helping with another person's child), and if you realize that it doesn't seem that bad after all, then your preferences have already shifted and you'll know it.

Not sure what to do here, or not sure what to do more generally?

Welcome! I hope you find this community as useful as I have.

—As others have suggested, reading the sequences is extremely useful and I wholeheartedly recommend it. However, it's also really long. If you want to start with something less huge, there's some good stuff here.

—Consider saying more about yourself here or in this thread.

—Where do you live? There might be an in-person meetup nearby.

Read the Sequences.

How did you find the site?

I am new here, and I am not sure what to do.

I think most LWers would advise you to read the Sequences, but I reckon you could get 80% of the value from doing so by reading two of the following four books (which would be much less time consuming):

1. Harry Potter and the Methods of Rationality by Eliezer Yudkowsky

2. Gödel, Escher, Bach: An Eternal Golden Braid by Douglas Hofstadter

3. Good and Real: Demystifying Paradoxes from Physics to Ethics by Gary Drescher

4. Thinking, Fast and Slow by Daniel Kahneman

Why are you here? Describe in the Welcome thread to get feedback.

New stuff is less helpful than you'd think it is. Start with the lesswrong Sequences (just google it, too lazy to make a hyperlink).

The CDC publishes stats on causes of death. Motor vehicle accidents, accidental poisonings, and falls are the major accidental, non-disease causes of death.

To reduce the chance of a motor vehicle accident, do what the car insurance companies recommend. They have a big financial incentive to be right.

To avoid poisoning, don't mess around with drugs. Overdoses of prescription painkillers and benzodiazepines (Valium) are common causes of poisoning; cocaine and heroin overdoses are also up there. It isn't clear to me how many of these overdoses might be misreported as accidental to avoid talking about suicide, but don't commit suicide either.

My wife and I have decided we're going to homeschool our son, almost five, for various reasons.

You might want to look into the idea of unschooling.

My wife and I have decided we're going to homeschool our son, almost five, for various reasons. What age do you think it would be appropriate to start rationality training, and how would you go about it?

Certainly before they reach five.

(1) Kids want parents to do stuff. Most parents rely on their authority and don't give their kid what it wants, even if the kid is able to provide valid reasons. A good way to teach rationality is to avoid to rely on arguments by authority.

My father had the policy of always giving me the real reason when I asked for something whether or not I would be able to fully understand the answer. That taught me that it's okay to get answers to questions that I don't understand. It was a valuable lesson for me.

Dumbing things down and relying on authority for arguments are the two biggest things that parents do to avoid their children being rational.

(2) When it comes to giving out pocket money consider giving it out as betting money. Let's say the allowance is $3 per week. Whenever the kid disagrees with you about a factual matter, he's allowed to ask you for your odds.

So the kid thinks it's raining. You don't think so and are pretty certain. So you say you have 4:1 odds. The kid can bet $1 from his betting money. If he wins the bet than he get $4 in real coins from which he can buy something.

The pocket money is motivating so he will have a huge incentive to get good at having accurate confidence in his beliefs. After a while he might even give you some rationality lessons.

(3) I would think about teaching a five year old Anki for all occasions where he has to learn something.

Now would be good? You can probably construct appropriate questions for a five-year-old based on the Eliezer's version of the fundamental question of rationality: "Why do you believe what you believe?". This can apply to a playground fight as much as to a big political issue.

for various reasons

Pray tell. Or just tell, no praying required, that would be telling. Just prying. Required, I mean.

What age do you think it would be appropriate to start rationality training, and how would you go about it?

About 3. How old is your son again? What are you, a bad father? No worries, it may not yet be too late, if you wake him up and start now. Just ingrain the rationality training as an aspect of the way you interact with him, I go for the Socratic Method. Don't set apart "rationality training" time (or are you planning to be irrational unless rationality is scheduled?!). Helping your kid develop mental models of others is my favorite. "Why is that person doing that, what does he want to achieve with that? What else could he do? Is what he doing the best way of reaching his goals? Yea, well done, now give the ice cream man his money, he's looking at us weirdly."

(Also keep in mind the "kids do as you do, not as you say" paradigm when interacting with others in the presence of your kid. Could lead to some strange conversations with the janitor, but aren't they always. Strange, I mean.)

Edit: Tone for comedic purposes, here's a special message to the downvoter(Edit:)s.

Oh, hey, we're almost exactly the same age.

You've got a lot going for you. You can program, you can write, you can enjoy working, you have at least some college education. This is enough to build on.

Based only on this post, it looks like your biggest problem is your social paralysis. Solving this problem isn't easy, but it's possible. Comfort zone expansion (CoZE) seems like the recommended model for training these skills. Try doing things that are possible but make you feel awkward—say, spend five minutes at a social event and then leave, or eat a quick meal in the kitchen, or something. Don't worry about doing these things confidently or well. It's supposed to be difficult and terrifying; when you do something terrifying and the world doesn't end, your brain will be less terrified to do it in the future. This should hopefully expand your comfort zone until you can eventually ignore strangers rather than flee from them, or ask your parents what they'll use your money for instead of living in uncertainty.

Your relationship with your parents sounds really destructive. Changing that should be high priority, whether it's by moving across the country or group therapy and reconciliation or whatever. I don't think income is the biggest barrier to your independence. Mediocre programmers can do pretty well (and can often work from home), and you say you own property, which can presumably be rented or sold. I'm more worried about your independent-living skills; being able to manage the dozens of mundane tasks that parents take care of (e.g. buy groceries, get an air filter changed, pay bills on time) can be a struggle for a lot of people when they first move out. Reddit threads about "life pro tips," or whatever the kids are calling it these days, will be your friend.

I have no idea how much blindness might exacerbate the problem. In any given city, there might or might not exist disability services that can help. My mom would probably be able to find out; let me know if I should ask her about any place in particular.

Applying to App Academy is exactly the kind of proactive, courageous thing you should be doing. Please take a moment to bask in my approval. The program sounds like it could provide everything you need, but it's definitely high risk. You'll be in a crucible where you have to live on your own, take care of yourself, and interact with humans. Either you'll be forced to grow into a significantly more competent human being, or else you'll get overwhelmed and burn out. If you get accepted (although my understanding is that such places are competitive) and decide to go, you'll want to take what precautions you can. Work with the program to set up the supports to make sure you succeed. Leaning on the local rationalist community to do this in parallel, as you mentioned, is also a really great idea.

If you don't go, do what you can to build your independence as soon as possible. You need those skills. Maybe you could do freelance coding online? Maybe you could move into that property you own? I don't know. Change something.

You're in a shitty place for now, but it looks like you're on track to change it. You can gain the social skills, independence, and self-confidence you need to accomplish your goals. People in your situation have done it before. Mostly it seems to require the courage to actually try, and you already have that.

After buying an e-cig, I never bought another pack of cigarettes. It has been roughly six weeks, I think. My consumption was slightly higher than yours.

I bought my roommate an ecig and he hasn't gone back after ~6 weeks.

Feel free to profit off the hours of research I did, this is what I bought: http://www.chinabuye.com/ego-t-travel-pack-metal-box-450mah-quit-smoking-usb-rechargeable-electronic-cigarette-e-cig-black-1

extra batt: http://www.chinabuye.com/450mah-capacity-ego-ce4s-battery-for-electronic-cigarette-black

The US distributors just slap their badge on these and double the price. you'll need extra clearomizers (or one of the other cartridge types) + ejuice, but that is up to personal preference.

Have you tried making yourself throw up immediately after (or even better, while) smoking?

I just logged back on after a brief absence from the site (a few days) to find I seem to have been genuinely karmassassinated. As far as I can tell, every comment I ever made has been downvoted, which was apparently enough to put me from 1200+ karma to -80

Wow! That's the first serious karmassassination I have become aware of. People do pissweak karma assassinations every now and again but I haven't seen a serious 1,300+ kill. I'm frankly surprised anyone bothered.

(although oddly, the "last 30 days" thingy claims I only got -148 karma; maybe it's maxed out?)

The last 30 days measure is only for votes on comments that were written in the last 30 days, not votes received in the last 30 days. The initial implementation included all votes received but had the effect that certain users could sometimes stay on the Top Contributers, 30 days list even if we didn't log in.

I understand it's possible to check who downvoted comments? It was probably a generically-named sockpupuppet, I guess, but still.

Possible, sure. I'm not sure how convenient it is. It may require direct database access.

EDIT: great, I apparently need to wait 8 minutes because I already commented. Did not know low karma did that.

Now usually when I see people complain about this I think "Working as intended! Downvote!". But this is a clear exception. Assassination is certainly not intended. I hope someone is able to sort this out for you.

The "last 30 days" score gives you a score for posts/comments that you submitted in the last 30 days, not the downvotes/upvotes you received in that duration. So if people downvoted comments of yours from further back, it wouldn't be counted.

I understand it's possible to check who downvoted comments? It was probably a generically-named sockpupuppet, I guess, but still.

I understand that there is a limit on downvoting -- it doesn't cost karma, but it's only possible up to the limit of one's karma, or something like that. If so, a sockpuppet wouldn't have enough karma. It must have been an account with a real presence here, either bingeing on OCD or using an automated script.

It's amusing that someone would care enough about LessWrong karma to view it as worth this sort of effort. As character assassination and revenge goes, that's pretty weak sauce. I suspect they got more disutility from wasting their time downvoting than you did by actually losing the karma.

A possible solution would be that one be required to solve a CAPTCHA before casting a vote if one has cast more than 100 votes or more votes than one's last-30-days net karma (whichever is less) in the past 24 hours.

Um, can any administrator types chime in on this? Apparently it must have been an established user, so it would be nice to find out who it is so they can at least get mocked for taking the Karma system so seriously (very passé).

Also, y'know, all those features that prevent passing trolls from annoying people too much are also applying to me, so if it's possible to reverse this that would be nice too.

EDIT: bump bump.

Nope, you're not the only one. Yikes! Thanks for the heads up, we'll look into it.

My remembering of a standard exposition (found the source, see edit) goes like this: a beautiful waterfall is a complicated dynamic system, containing many more atoms than a human brain, all in motion. Were one clever, one could map the motion of water in part of the waterfall to motion of atoms and charge in a human brain. Then the waterfall is a person, thinking thoughts as it burbles. Except there is a problem, where each waterfall has many possible mappings, and thus spans the whole range of brains!

If one then asks the question "so why aren't you a waterfall?" this is a sort of epistemological analogue to the Boltzmann brain hypothesis.

I seem to recall the original argument going a different place: "are waterfalls on-average blissful or suffering, and by how much do billions of waterfalls encoding all possible minds outweigh our petty human concerns?"

EDIT: Ah, found the source (ctrl+f "waterfall"), which references Putnam and Searle, and is worth a read in its entirety. A little discussion of ethical implications on LW can be found here.

my interests overlap only somewhat with those of the Lesswrong community. I'm not especially interested in AI friendliness or existential risk

This is not uncommon in the LW community. Artificial intelligence, personal rationality, effective altruism are the three big topics here, but many people are interested only in one or two of them.

Would this be the best place to introduce onesself?

That would actually be the welcome thread, but this is a close second best.

It's your lucky day.

From the latest census

Liberal: 427, 36%

Libertarian: 359, 30.3%

Socialist: 326, 27.5%

LW used to be Libertarian dominated, but as it's grown it has gained more and more progressives.

As discussed, I have a new version which preserves the proof structure, but weakens the premises about as much as possible.

A1. The collection of all entities is a set E, with a causal relation C and a partial order P, such that x P y if and only if x is a part of y.

Note: This merges the assumption that P is a partial order into the overall set-up; that feature of P now gets used earlier in the argument.

A2. The set E can be well-ordered.

This ensures we can apply Zorn's Lemma when considering chains in E, but is not as strong as the full Axiom of Choice. If the set E is finite or countable, for instance, then A2 applies automatically.

Definitions: We define a relation C* such that x C* y iff there are entities v, w such that v P x, y P w and v C w.

Note: This gives a broader causal relation which automatically satisfies "if x C* y and x P z then z C* y" as well as "if x C* z and y P z then x C* y", loosely "anything which is caused by a part is caused by the whole" and "anything which causes the whole, causes the part". So we don't need to state those as extra premises.

We then define a further relation <= such that x <= y iff x = y, or there are finitely many entities x1, ..., xn such that x1 = x, xn = y and xi C* xi+1 for i=1.. n-1.

Note: This construction ensures that <= is a pre-order on E.

Say that a subset S of E is a "chain" iff for any x, y in S we have x <= y or y <= x. Say that S is an "endless chain" iff for any x in S there is some y in S distinct from x with y <= x. We shall say that y is "uncaused" if and only if there is no z in E distinct from y with z C* y (this of course implies there is no z distinct from y with z C y, but it also implies that y isn't part of anything which is caused by something distinct from y). Say that x is a proper part of y iff x is distinct from y but x P y.

A3. Let S be any endless chain in E; then there is some z in E such that every x in S is a proper part of z.

Lemma 1: For any chain S in E, there is an entity x in E such that x <= y for every y in S.

Proof: Suppose S is not endless. Then there is some x in S such that for no other y in S is y <= x. By the chain property we must have x <= y for every member y of S. Alternatively, suppose that S is endless, then by A3, there is some z in E of which every x in S is a part. Now consider any y in S. There is some x not equal to y in S with x <= y, so there are entities x = x1... xn = y with each xi C* xi+1 for i=1..n-1. Further, as x P z we have z C* x2 and hence z <= y.

Lemma 2: For any x in E, there is some y in E such that y <= x, and for every z <= y, we must have y <= z.

Proof: This follows from Zorn's Lemma applied to pre-orders.

Theorem 3: For any x in E, there is some uncaused y in E such that y <= x.

Proof: Take a y as given by Lemma 2 and consider the set S = {s: s <= y}. By Lemma 2, y <= s for every member of S, and if S has more than one element, then S is an endless chain. So by A3 there is some z of which every s in S is a proper part, which implies that z is not in S. But by the proof of Lemma 1, z <= y, which implies z is in S: a contradiction. So it follows that S = {y}, which completes the proof.

We now partition E into three subsets. I are the "inert" entities, which do not cause anything and have no causes themselves. (Note that the new version allows there to be some of these, unlike the previous version; you can think of them as abstract entities like numbers, sets, propositions and so on, if you want to). Formally I = {x in E: there is no y distinct from x with x C* y or y C* x}. U are the "uncaused causes" - formally U = {x in E: there is no y distinct from x with y C* x, but there is z distinct from x with x C* z}. O are all the "other", caused entities, so that formally O = {x in E: there is some y distinct from x with y C* x}.

B1. If S is any subset of U such that for any x, y in S we have x P y or y P x, (call such an S a "chain of parts"), then there is some entity z of which all members of S are parts.

B2. Suppose that y <= x and z <= x. Then there is some entity w such that: w <= x; w <= y or y P w; w <= z or z P w.

(EDIT: Restated to ensure that Theorem 4 properly follows.) Informally, the idea is that y and z can't independently cause x without any further causal explanation. So there must be some common cause, however each of them may be part of that common cause.

Definition: Say that entities x and y are causally-connected if and only if x=y or there are finitely-many entities x=x1,..,xn=y with each xi C* xi+1 or xi+1 C* xi for i=1..n-1.

B3. Any two entities x, y in O are causally-connected.

Informally, O doesn't "come apart" into disconnected components, such as a bunch of isolated universes. Premises B1-B3 turn out to be necessary for Theorem 6 to hold, as well as sufficient (see below). So they can't be made any weaker!

Theorem 4: For any x in O, there is a unique entity f(x) in U such that: f(x) <= x, and any other y in U with y <= x satisfies y P f(x).

Proof: For any x in O, define a subset U(x) = {y in U: y <= x}; this is non-empty by Theorem 3. Consider any chain of parts S that is a subset of U(x). If it has at least two members, then by B1 there is some z in E of which all members of S are parts, and such a z must be in U. (If not, then note any w C* z would also satisfy w C* s for each member s of S, which would require them all to be equal to w). Also since y <= x for any member of S and y P z we have z <= x. So z is also a member of U(x). Or if S is a singleton - say {z} - then clearly all members of S are parts of z, and z is also in U(x). By application of Zorn's Lemma to U(x), there is a P-maximal element f(x) in U(x) such that there is no other y in U(x) with f(x) P y. By B2, for any other y in U(x) there must be some z in U(x) with f(x) P z and y P z; given f(x) is maximal we have z = f(x) and so y P f(x). This makes f(x) the unique maximal element of U(x).

Theorem 5: For any x, y in O, f(x) = f(y) if and only if x and y are causally-connected.

Proof: It is clear that if f(x) = f(y) then x is causally-connected to y (just build a path backwards from x to f(x) and then forward again to y). Conversely, consider any two x, y in O:

a) If x C* y, then f(x) is in U and satisfies f(x) <= y so we have f(x) P f(y). Since x is not f(x), we have f(x) C* x2 <= x for some x2, and hence f(y) C* x2 <= x i.e. f(y) <= x which means f(y) P f(x), and so f(x) = f(y).

b) If z is in U with z C* x and z C* y, then z P f(x) so f(x) <= y and f(x) P f(y); similarly, f(y) P f(x) so that f(x) = f(y).

The result now follows by induction on the length of the causal path connecting x to y.

Theorem 6: If O is non-empty, then there is a single entity g in U such that: f(x) = g for every x in O, and y P g for every y in U.

Proof: Assuming O is non-empty, take any element y in O, and set g = f(y); then the result that f(x) = g for any x in O follows from Theorem 5 and B3; further, for any y in U, there is some x in O with y C* x, so by Theorem 4, y P f(x). If there are no elements of O (meaning there are none in U either) then the Theorem is trivial.

Finally, note that B1, B2 and B3 are entailed by the statement of Theorem 6. For B1, we can just take g as the relevant z. For B2, we can take g as the relevant w. B3 follows using using the first part of Theorem 5 (just track from x back to g, then forward to y again).

I'm just about done now, so unless there are errors in the above proof will leave it. What are the residual weak points? Well, B2 and B3 have been weakened a bit, but are still basically unjustifiable (we can imagine them being false without absurdity) and the above re-work shows they are needed for the uniqueness conclusion (Theorem 6). Also, we have the weakness of not deriving anything else useful about g.

Looking over the "recipe" again, I notice one thing I failed to notice earlier; at no point have you formally defined the uncaused cause as God. That's a weak step, but if you actually want to use that argument to argue for monotheism (instead of merely the presence of an uncaused entity, nature unknown) then I think it's a necessary step. Some of the assumptions necessary to eliminate multiple uncaused causes are a bit weak, but I think that you have a very good argument that somewhere in the history of the universe there must be at least one uncaused cause of some sort.

I have spotted an error in the statement (and proof) of Theorem 5, and then Corollary 6. The issue is that for any uncaused y we must have f(y) = y, so if there are several uncaused entities then they can't all have f(y) = g. The revised statements should go like this:

Theorem 5: Let x and y both have causes. Then f(x) = f(y) if and only if x and y are causally connected.

Proof: It is clear that if f(x) = f(y) then x is causally-connected to y (just build a path backwards from x to f(x) and then forward again to y). Conversely, suppose that x C y, then f(x) is uncaused and satisfies f(x) <= y so we have f(x) P f(y); since x is caused, there are f(x)=x1,...,xn=x such that each xi C xi+1 for i=1..n-1, then by A3 we have f(y) C x2 and hence f(y) <= x, which implies f(y) P f(x) and so by B1 f(x) = f(y). Next, suppose that for some uncaused z we have z C x and z C y; then z P f(x) which implies by A3 that f(x) C y and hence f(x) P f(y); similarly, f(y) P f(x) so by B1 f(x) = f(y). By an induction on the length of any other path connecting x to y, we have that f(x) = f(y).

Corollary 6: There is a single g in E such that: f(x) = g for every x in E with a cause, and every uncaused y P g.

Proof: Suppose there is at least one entity x with a cause, then set g = f(x). For any other caused entity y, f(y) = g by Theorem 5 and B5, and for an uncaused y, B5 implies y <= x, so that y P g. Lastly, if there are no caused entities, then B5 implies that E = {y} for some uncaused y, so we can just pick g = y.

I have also spotted a way of weakening or removing some of the premises (in particular A3, and B1 to B4). I will update with that later today.

13 of the respondents to the latest survey said they were from Russia.

I think that's the kind of a thing that most people know in principle, but which is very hard to actually stick to when you have a raging hissy person in front of you, so it's good to be reminded of it every now and then.

So just a little reminder that may or may not be redundant among here: don't do this. Don't give more of a chance to the person who screams and acts crazy than to the person who tries to work things out with you the calm, mature way. It's exactly the wrong way to respond if you want to incentivize rational behavior on the part of the other party. The message is basically "I won't listen to any attempt at reasonable discussion, but try going hysterical on me, that one has good odds of success", thereby earning yourself more hissy fits in the future. And especially don't do this as parents, to your kids.

It is worth explicitly noting that this heuristic applies when, and to the extent that, influence over future behavior of the other person or witnesses is the dominant consideration. In a once-off encounter with a street thug or a bank robber different considerations apply. It is not always your responsibility to 'train' people.

Being angry is a signal that you're willing to back up your disagreement with consequences of some sort, whether it's violence or a lost friendship. It's also a signal, commensurate with the degree to which it is embarrassing, that this is highly important to you. Why, precisely, is it irrational to respond to this? Did evolution prime us to respond to it because it thought it would be funny? It is, indeed, not obvious to me (though perhaps I have low IQ) that it is astonishingly stupid to be more convinced (behaviorally) by pathos than logos; behavioral reinforcement is but one concern among many, and whose value fluctuates in accordance with how many interactions you expect to have with this person, whether they are physically larger than you, &c. And the persuasiveness of logos, obviously, can rather depend on the quality of the logos. Maybe your logos isn't as good as you think it is? You apparently weren't able to discern why they were upset with you in the first place, which certainly would have placed a damper on your ability to articulate convincing reasons why they should not.

The UN has those numbers. I've only used the old version.

1) Find academic papers on the subject, see where they got their data 2) Data-only search sites like Zanran, or set google to search only for .xls 3) Question and answer sites, like r/datasets

The coin was made in one of several ways. (Perhaps these ways are parametrized by the ratio of weights between the two sides of the coin.) You have a subjective probability distribution over this set W of possible ways in which the coin was made, according to which p(w) is the probability that the coin was made in way w. This distribution should come from a maximum entropy prior incorporating all your knowledge about the origin of the coin.

Furthermore, for each way w in W, you have a conditional probability p(H | w), which is your subjective probability that the coin will turn up Heads given that the coin was made in way w. This conditional probability distribution incorporates your physical knowledge about how weight ratios in coins influence the dynamics of their flipping.

Finally, you compute the unconditional probability p(H) that the coin will come up heads by summing up the values p(H | w) * p(w) over all ways w in W.

These texts can work as an introductory undergraduate sequence (with "Sets for Mathematics" going after enough exposure to rigor, e.g. a real analysis course, maybe some set theory and logic, and Awodey's book after a bit of abstract algebra, maybe functional programming with types, as in Haskell/Standard ML/etc.):

• F. W. Lawvere & S. H. Schanuel (1991). Conceptual Mathematics: A First Introduction to Categories. Buffalo Workshop Press, Buffalo, NY, USA.
• F. W. Lawvere & R. Rosebrugh (2003). Sets for Mathematics. Cambridge University Press.
• S. Awodey (2006). Category Theory. Oxford Logic Guides. Oxford University Press, USA.

I assumed it was just a way of saying different women fall into different reference classes for the purposes of estimating breast cancer risk (e.g. an alcoholic woman with a positive BRCA1 test result and a vitamin D deficiency vs. a teetotaller with no harmful BRCA mutations and no vitamin deficiencies).

There is no implicit assumption. She was apparently tested for BRCA1 based on family history, and was found positive. The correlation between BRCA1 and those cancers yields a certain percentage of risk, a calculation into which family history might also account. She links to here: http://cancer.stanford.edu/information/geneticsAndCancer/types/herbocs.html

Your third option is correct - although both effort, will and resources to acquire genetic testing are required.

Do they mean:

Who's they? You are reading a text written by Angelina Jolie for a general audience. She has to make certain that no woman reader who reads the story comes away with thinking that she also has a 87 percent risk.

I understand that not everyone is a Bayesian black-belt, but I am trying to figure out what implicity assumption motivates people to talk this way.

What does a Bayesian black-belt do, when the only numbers he has are come frequentist statistics that someone else did?

tDCS has come up before many times. Did you search the site and read previous comments?

I identify as a rationalist, not an atheist.

Beware of identifying in general. "We" are all quite different. Few if any of "us" can be considered reasonably rational by the standards of this site.

I think it's worth distinguishing ourselves from the "atheist" label.

With a sizable minority of theists here, why is this even an issue, except maybe for some heavily religious newcomers?

Living in rural America, where Atheism is still technically illegal in some places even though no one would dare enforce it, I think distinguishing the labels "rational thinkers" from "atheists" is a very good idea. I don't think someone who considers themselves rational and theist would be particularly proud to associate with the label that best fits their particular brand of theism (Roman Catholicism and Mormonism seem to spawn subverters of this expectation, but reducing to the common category of "christian" seems to invoke way more cultural baggage).

Or rather, I wouldn't dare call myself a christian or an atheist anywhere anyone could possibly find out about. Smart people would dismiss me as inferior for the former, 90% of people within a 200mi radius would start hurling crosses at me for the latter. Probably will need allies in both groups, so I'm kinda concerned about this whole labels thing.

I'm comfortable calling myself an atheist (though I rarely need to), but only because I believe in zero gods and that qualifies me for the label in the eyes of almost everyone. In other words, I treat "atheist" as a feature of my worldview, not as an identity. Sure, these evangelical atheists people are so concerned over might share that feature with me, but we also share opposable thumbs and a well-developed prefrontal cortex, and I'm not too worried about that.

This seems like a common enough take on the word that I don't risk misunderstandings unless I'm dealing with people from highly religious subcultures who've never met an atheist in the wild. Inadvertent identity pollution might be an issue if the set of atheists was more narrowly defined, but there's no agenda attached to atheism and precious little in the way of unifying features besides the obvious.

On the other hand, I'm distinctly uncomfortable calling myself a rationalist. Partly because the term has a philosophical meaning which is quite unlike that common here, but mostly because it implies adopting a subcultural identity, and that's playing with fire: ingroup biases are so pervasive, and so easy to accidentally fall into, that you should generally only do that when you have a positive reason to. Even if that weren't the case, LW is such a small group, and in many ways such a strong outlier, that dressing up a in LW-specific identity is going to carry far more baggage in the outside world than a term as broad as "atheist" would.

At least on LW and at the meetups I've been to, I haven't seen people claiming atheist identity. I agree with your prescription, but think most people obey it already.

happiness is what happens when things are going well, depression is what happens when things aren't, and the two moods must serve some sort of evolutionary function, right?

Depression causes inactivity, helplessness, not dealing with problems, cutting social ties, and sometimes suicidal behavior. It's hard to see how any of that could be evolutionarily beneficial in any scenario. (Which is not to say it's not an evolved behavior due to some different mechanism, like being tied to otherwise beneficial genes.)

We already know that a political dichotomy is game-theoretically mandated by the U.S. voting system. Which means we don't particularly need a separate and additional explanation for political dichotomies, and so I'd want independent evidence of other explanations.

and the two moods must serve some sort of evolutionary function, right?

Maybe depression is like the appendix, or a congenital skin rash, or food allergies, or male nipples, or the optic nerve being in backwards, or ingrown toenails, or the coccyx. In other words, sometimes evolution is just stupid.

I think depression is the wrong word there. Too clinical, too enduring.
I think you would be on stronger footing to use optimism and pessimism as strategies for thrive/survive; happiness and sadness are the feedback mechinisms letting you know if you are using the right strategy:

optimistic and wrong = failed expectations-> unhappy

optimistic and right = opportunity taken and paid off->happy

pessimistic and wrong = missed chances->unhappy

pessimistic and right = danger avoided