The Heritability of Everything

The gold standard in heritability estimates is the twin study, which involves looking at identical and fraternal twins, raised together or apart. This allows the cleanest test of decomposing the variance in observed traits into genetics, shared environment (factors equally affecting all children raised together), and non-shared environment (everything else, including random noise) contributions.

Generally it is assumed that the effect of parenting is equated with the shared environment, though there is clear evidence that parenting can differ substantially between siblings of the same parents and account for a significant fraction of non-shared environment, and the shared environment by definition also captures e.g. the neighborhood in which you grow up. Generally there are many caveats to apply to heritability estimates, particularly that they are only defined within a given population and may not apply as well in extreme cases, but nonetheless they are our best estimates as to the effects of genetics, and the effect is undeniably large.

An extremely ambitious meta-analysis of all twin studies was published in May 2015, reporting heritability estimates from 2,748 studies featuring over 2 million twin pairs, encompassing virtually every published study to date. The researchers have made a data visualization tool available if you wish to dig down into various aspects of the study, though it’s fairly opaque if you’re not familiar with the field’s jargon.

Across very broad domains of health outcomes, almost everything falls within the 40-60% heritability range, with cancer as a representative example being 46% heritable. Similarly, neurological variables show about 50% heritability (with little shared environment involvement), while cognitive and psychiatric outcomes are similarly heritable, but also have a nearly 20% shared environment component. Social values appeared to be 31% heritable, but shared environment played nearly as big a role at 27% explained. Similarly, social interactions were 32% heritable, with a somewhat smaller shared environment component of 18%.

Drilling down into more specific categories of interest, intellectual functions broadly were highly heritable at 67%, while more specific executive function metrics were 51% heritable with a high 24% shared environment contribution. Mood disorders were highly variable, from bipolar being 68% heritable to depressive episodes being 34% heritable. Height and weight showed 63% heritability, with relatively large 30% and 20% shared environment contributions respectively. The more specific values and social variables were mostly in line with the overall findings. Tendency towards religion and spirituality was 31% heritable with an even larger 35% shared environment component. Basic interpersonal interactions were similar, with 30% heritability but 36% determined by shared environment.

To summarize, basic variables in terms of intelligence, height, and weight are primarily determined by the genetic contributions. Most health and psychiatric outcomes fell somewhere in the middle, but still showed roughly half of variance explained by genetics. Variables relating to fundamental values (e.g. religion, politics) and social interactions (e.g. emotional intelligence, relationships) were by far the most malleable traits, with roughly equal contributions from genetics and shared environment.

What Has Changed my Political Beliefs

I think it’s safe to say that political beliefs are one of the most sticky types of beliefs we commonly hold. By some measures partisan polarization is at record highs for the modern era (though these figures are also debated). Politics are also beliefs that provoke some of the strongest arguments between differing viewpoints, and the strongest consolidation among shared viewpoints. Eliezer warned us to be particularly careful when grappling with these ideas.

But, as good rationalists, all of our beliefs should be subject to updating upon receiving further information – and when I look at my political beliefs over the years, I see that they have indeed changed, in some ways massively, in other ways slow and subtly. I thought it would be an interesting to lay out what the drivers of these changes were, as a case study in the art of changing one’s mind.

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Summary of How To Talk So Kids Will Listen & Listen So Kids Can Talk

How To Talk So Kids Will Listen & Listen So Kids Can Talk is a parenting / communication book written by Adele Faber and Elaine Mazlish. While this book is specifically intended for parents to have better relationships with their children, the vast majority of the advice contained within applies universally to all interactions, and I have written this summary specifically to abstract away from parent-child relationships. I consider the first chapter alone better at helping people internalize the principles behind nonviolent communication than Rosenberg’s entire book. HTTSKWL is currently by far my most highly recommended communications book, and because it is appealing to parents and children it is a remarkably easy read.

Note that unlike most books, this one contains a very high ratio of exercises and prompts and anecdotes relative to its advice. The authors recommend going through the book slowly, and doing all the exercises. This summary will only contain their explicit instructions – I highly recommend buying a copy of the book and completing it. The many specific example conversations will give a much better understanding of the principles I lay out here than I can convey in a summary.

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A Theory of Economic Development

If I had to give the Most Underrated Professor Award to anyone I studied under, it would easily have to be Professor Meir Kohn. His work falls squarely outside the paradigm of mainstream economics, which (coming from me anyway) could not be a higher compliment – yet also makes it difficult to get traction inside the field. Kohn himself wrote a great essay contrasting the mainstream paradigm of Samuelson and Hicks with the lineage of more qualitative thinking descended from Adam Smith, including fields like economic history and new institutional economics and public choice theory among others.

He has been working on a theory of economic development for two decades now, and in my opinion it appears to be substantially correct. He first composed an unpublishable opus about European economic development from 1000-1600, which I read in its entirety. Then he wrote a more condensed version, where he applied the theory to China as well as Europe, which is likely going to be published in the next couple of years. In private correspondence, he has indicated that he and his students are now applying the model quite successfully to analyzing other economies throughout history.

The first chapter of his first opus contains the best description of his overall model I have yet read. Because I hold it in high regard, believe it to be fundamentally true, and I refer to it often, I am posting my summary of it below. All errors and omissions are mine.

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(Partial) Summary of A Theory of Moral Sentiments

Adam Smith is best known for being the father of modern economics with the publishing of his magnum opus The Wealth of Nations. Far fewer people know about his second most famous book A Theory of Moral Sentiments (which, incidentally, is where the term “invisible hand” actually comes from). While the book is nominally about moral philosophy, I think it would be more accurately described as a work of psychology: Smith is trying to explain how morality arises from the workings of our minds. Much in the same way that The Wealth of Nations still seems surprisingly insightful today, I posit that A Theory of Moral Sentiments accurately described aspects of human psychology that were not appreciated until much later. I enjoyed listening to the EconTalk book club on ToMS as well, if you want to have a lively discussion with lots of background and historical context.

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Understanding Body Language, Touch, and Appearance

When it came to understanding body language, fashion, all of that kind of stuff, I used to be a typical clueless nerd. I didn’t perceive it, and I didn’t think it really mattered.

I know better now.

It matters. A lot.

Over the years I have seen a lot of objections to learning to perceive this kind of thing on a conscious level – but notably these objections tend to come from people who already know how to do it! For those of us who never learned how to perceive these things by default, there is little choice but to go through the usual conscious incompetence route at first, and I wholeheartedly support any geeks who want to learn how to get better at the things that everyone else already does.

To that end, I have written up notes on body language, touch, and appearance, which systematize most of what I know about these important social variables, and I want to make them available to anyone who wishes to learn this stuff. It can be a challenging and even overwhelming road at first, but I think it’s an incredibly important life skill. Remember that social interaction is a positive sum game. You can have increasing social success and other people will find you more fun to be around!

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How to Build a Tribe

It is important to preface this entire document by saying that I had very specific objectives for creating a tribe. In particular, I wanted a group that was emotionally vulnerable with each other, who are reacting in real time to each other’s responses, where we create a safe space to say and feel and process anything. If you’re looking for something else, only some of this will apply to you. If you share this vision with me, a list of concrete steps to get there from here is below the fold:

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How to Deal with Email

One of the biggest problems that I commonly hear from my friends is that processing email is completely unmanageable. The most important thing to remember is that your attention is the most precious resource that you have, and you need to guard it jealously. All of the following principles flow from this fundamental insight. The following seven steps will get you most of the way towards inbox sanity.

Turn Off Email Notifications

The very first step you need to take to reclaim your valuable and limited attention is to turn off any form of email notification. If your phone vibrates, knock that off immediately. If your mail client gives you a popup or rings or displays a red badge, change the settings. If you are keeping your inbox open in another tab and see new emails coming in, close it. By having your devices constantly pushing email on you, you will be constantly tempted by email and switching between tasks repeatedly, which is a disaster for productivity.

The most common pushback I get on this point is that sometimes there are legitimately urgent messages that need to be answered. In some cases this may be true, but for the vast majority of people what is the worst case scenario? We have a different method of dealing with urgent concerns, and that is called a telephone—call or text will do. If you need to respond to emails for work, go to the people who need you urgently and explain the situation. You are very busy and constant emails are distracting you from important tasks, ask them to give you a quick call when they urgently need your attention.

Unsubscribe from Everything Immediately

By this point, it has probably become habitual to scan over your inbox and either ignore (or preferably archive) specific sources of messages — maybe this is a company that keeps emailing you about its latest deals or products, for instance, or maybe this is some noisy Facebook group that a distant acquaintance thought you would enjoy. Regardless of how quick and easy you think it is to get rid of these things, you are incurring a small penalty of time and attention again and again to even glance at the email. So from now on, you have a new habit: unsubscribe from everything the first time you no longer want to read it. This takes a little bit of upfront time — usually one or two clicks, maybe typing your email or unchecking boxes—but it saves you precious seconds every time you look at your inbox. You would be shocked how quickly you recoup that particular investment.

Some lists are worth staying on—maybe you’re on the mailing list of your favorite author because you actually want to be notified when he’s in town, or maybe you’ve signed up for an email course or some daily tips that you actually read. Maybe your favorite fanfic is constantly being updated, and being notified when the new chapter is up prevents you from obsessively refreshing your browser. Pay attention to your behavior. Once your eyes start preemptively glazing over when you see an address, you know it’s time to unsubscribe.

Create Filters

There is an intermediate step between emails you want to know about immediately and ones that you never want to read, and for this purpose some brilliant software engineers created filters. Any emails that you receive on a regular basis are extremely good candidates for filtering.

For some personal examples, I have a filter that sends all emails originating from Meetup to their own special folder. Any time I am wondering what is going on in town, or if I have a free evening to kill, I have a host of events available to me at the click of a button. I do something similar for mailing lists, which routinely contain interesting information that I do intend to read — at my leisure, that is.

Batch Process Email

Now that you’ve greatly reduced the number of incoming emails, you are in a much better position to deal with your inbox. You have also stopped your devices from constantly distracting you, so you’re not constantly processing emails — from here on out, processing email is a deliberate choice on your part. You will pick exactly when and where you want to deal with emails, and not a moment before. When you have an unbroken block of time — and this may even be worth explicitly scheduling — you should sit down and continue processing emails until you run out of time or are finished. (What does ”finishing” email even mean? Keep reading!)

By the way, in case this is not abundantly clear, you should always do batch processing of replies from a computer with a full keyboard. Mobile keyboards are simply not designed for rapid typing in the same way. The kind of batch processing that you can do on a mobile phone is that of reading and archiving emails — which allows you to focus immediately on responding when you get to a computer. Leave anything that requires a non-urgent response for later.

Minimize Replies

The first principle I introduced was about reducing the number of incoming emails, and now it is time to look at the other side of the equation. Writing emails takes even more time than reading them, so if anything this step is even more critical! You can follow one very simple heuristic here: shorter is better, and replies that never get written are the shortest ones of all. And that’s it!

Ironically, I didn’t learn this lesson for myself until I finally caved in and got myself a smartphone. I am the king of verbose emails, I love to write paragraph after paragraph in response to just about anything. Ask me a question and I will go on at great length. Well, I very quickly gave up on the idea of composing long emails using the smartphone’s keyboard. In fact, I learned to become as parsimonious with my words as possible, because it was so aggravating. And you know what? Nothing changed. If anything, I got faster responses from shorter emails! No one was upset I didn’t provide them with reams of information. This was so striking that I changed my email signature to say: ”Sent from my smartphone, enjoy the unusual brevity.” And I never looked back.

There is one situation where I believe that a quick reply is better than no reply, and those are the emails sitting at the bottom of your inbox the longest, the ones you have been putting off indefinitely because you really want to do them right This was one of my biggest personal challenges in dealing with my own inbox, especially given my propensity towards long emails. It still hurts me that I put off the most important emails for weeks, or months, or sometimes even forever, because I wanted to write a long reply and simply never had the time or motivation. I failed to congratulate people on major life events, or catch up with old friends, or follow up important leads, because I didn’t think I could get away with a quick response. But the truth is, a quick response to an important email is better than no response at all. Please don’t leave the most important parts of your life to ferment at the bottom of your inbox.

Be Realistic

Your colleague sees a funny video and emails it to your group, or an old friend of yours sees an article and thinks of you. While these are kind and even important gestures, there are simply only so many hours in the day. There is already more content out there than we could consume in our entire lives, so we need to prioritize where we direct our attention. One type of email that I tend to keep around is something that seems like it could be really interesting, but never quite get around to looking at. So what is my solution? I collect all of these links and I put them in a separate file or bookmark folder. When I have a spare moment and think about it, I go back and look at them. Some of them you will probably never get around to, and that’s okay. Be realistic about how you are going to spend your time, and don’t waste any of it agonizing over whether or not to consume content.

Inbox Zero

So what is the end result of all of this advice? Quite simply, to have zero emails left in your inbox at the end of processing. This should be the default resting state of your inbox: you are either ignoring email entirely, or your inbox is empty, end of story.

The archive button is your best friend. Every time you finish reading something, archive it. Every time you send a reply, archive it. (Note that Google Labs has a ”Send and Archive” button that seriously comes in handy here.) Every time you add another link to your ”eventually” list, archive it. When you get an email about coordination or scheduling, enter it into your calendar immediate and then archive it.

After your initial quick pass over the inbox to clear out most of the items, everything remaining should be something that is awaiting either immediate reply or action. After you do what is necessary, archive it. If something is sitting in your inbox that you don’t intend to do until later, then add it to your to-do list, flag the email or send it to a special folder, and then archive it.

…and there you have it: a pristine inbox. Doesn’t that feel relaxing? Your inbox induces no cognitive load whatsoever! You are never left feeling guilty, or wondering if something slipped through the cracks, or worrying about replying to important emails. Everything is exactly where you put it, and you know just where to look to find it.

Low Hanging Fruit for Health and Wellness

Include in Diet

Fish or cod liver oil: excellent source of omega-3 fats which most people are severely deficient in, take 1-2 tsp/day.  These fats are fragile molecules and can go rancid easily, so store them in the refrigerator.  If you buy capsules, bite into one occasionally to test for bitterness.  I buy the oil in translucent glass bottles online, sealed with vitamin E and nitrogen – I recommend Carlson’s or Nordic Naturals, check before you buy!

Liver: the most potent single food in terms of vitamin and mineral content, in a form that is easily absorbed by the body (much better than a multivitamin).  Eat at least 4 oz/week for optimal health.  You can find grass-fed liver at local farmer’s markets, or frozen liver in most grocery stores.  If the taste of beef liver is too strong, switch to calf or chicken liver, or soak it in milk for at least 30 minutes before cooking.

Grass-fed butter: excellent source of healthy fats unique to dairy products, and fat-soluble vitamins.  Kerrygold is the most commonly-available brand of grass-fed butter.  Grass-fed ghee is often available in specialty ethnic stores.

Coconut oil: the medium-chain triglycerides are metabolized by the body in a unique way, and promotes cellular repair mechanisms.  You can buy in bulk online, for instance at Tropical Traditions.

Remove from Diet

Sugar: probably the least controversial thing on this whole list!  In general, cutting back on sweets means you will lose the taste over time.  Liquid sugars like soda and fruit juice are the worst offenders, drink coffee or tea or flavor water with fruit instead (diet soda may not have calories but it maintains that sweet craving).  Pure solid sugar like candy can be replaced with fruit, which has water and some vitamins in addition.  For replacements, try using the natural non-caloric sweetener stevia, or buy dextrose powder (a fructose-free sweetener) online.

Vegetable oil: primary source of inflammatory omega-6 fatty acids, unfortunately it is very common in the food supply.  First, avoid deep fried foods entirely, because heated omega-6s are highly unstable.  Avoid margarine or vegetable shortening, which contain trans-fats.  When eating out, ask for your food to be cooked in butter.  When eating salad, stick to olive oil and vinegar, as most dressings have a vegetable oil base.  Never use this in your own home!

Grains and legumes: your mileage may vary on these foods, if you want starch then try to mostly eat root vegetables like (sweet) potatoes.  Many people have problems with gluten, found primarily in wheat, barley and rye – stores will often have a gluten-free section with alternatives.  Most people tolerate rice and corn well, so substitute rice pasta and corn tortillas.  Opt for sprouted or sourdough-fermented bread over white or whole wheat.  With legumes, see how your GI tract responds.  Soaking, sprouting, fermenting and cooking all improve digestibility.  Soy is particularly bad since it has chemicals that mimic estrogen. Peanuts are also strongly immunogenic.

Non-Dietary Measures

Vitamin D: ideally produced from sunlight, but more practically supplemented.  To get enough from sun you need a UV index above 3, which happens in the tropics and during spring and summer noonday sun in temperate regions.  For someone with pale skin, 15 minutes front and back of full-body exposure between 10 AM – 2 PM gives you the maximum dose.  When not exposed to this amount of sunlight, supplement at least 2,000 IUs/day (and no more than 10,000 IUs). Ideally, get your blood levels tested regularly and find out what dose keeps you in the optimal range.

Sprinting: anaerobic exercise gives you all the benefits of aerobic exercise and then some, releasing beneficial fat-burning hormones and encouraging mitochondrial proliferation.  Sprinting requires no equipment, and only minutes of work!  Alternate 20 seconds of max-effort sprinting and 10 seconds of rest for 8 intervals, twice/week.  This will be very difficult at first, but it gets easier each time – if 10 seconds of rest is not enough, you can rest for longer periods between each interval and sprint harder.  You don’t need any more exercise than that to see benefits, unless you want to build muscle or have fun!

Sleep: the second-least controversial thing on this list, chronic sleep deprivation has numerous health consequences and acute sleep deprivation just doesn’t feel good.  Go to sleep early enough that you don’t need to wake up to an alarm clock.  If you are not getting tired at night, try eliminating sources of blue light from your bedroom (or wear Uvex orange glasses before bed), and take 300 mcg melatonin an hour before sleep.  If your mind is racing, try writing those thoughts down on a piece of paper, or go talk to a friend!

Intermittent fasting: useful to get your body into fat-burning mode, encourage cellular repair, and generally give your body a break from metabolism.  This will be much easier once you have transitioned to a high-fat diet, since fasting through hypoglycemia is unpleasant.  Due to the hormone ghrelin we get hungry around habitual meal times, but this effect fades within days.  The easiest way to create a longer fast is to skip one of the meals around sleep, either breakfast or dinner, whichever is easier for you.  Work your way up to a 16 hour window daily – and longer if you feel like it!

Hypothetical Apostasy on Nutrition

As many of you know, I am a major proponent of paleo/primal/ancestral/etc type diets. At this point the term “paleo” has come to be applied to many very different diets, but for the record my own personal beliefs coincide most strongly with the Perfect Health Diet. Whatever you want to call it, it is certainly outside of conventional wisdom and mainstream scientific/medical opinion. This has been a point of contention between me and others who put more stock in mainstream opinion. I have spent many hundreds, or maybe thousands, of hours doing research into human metabolism, and as a result my ideas are starting to get sticky.

Periodically I like to subject my beliefs to one of my all-time favorite techniques, the hypothetical apostasy by philosopher Nick Bostrom. The basic idea is to produce a good faith effort at destroying your currently held position. This process has helped me improve my thinking on a number of topics, including the original mind-killer itself: politics. Given my particularly strong beliefs about diet, it is long past due for me to try this exercise. Below the fold is my best attempt to undermine the paleo position:

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