Hujambo! Welcome to this week's digest. In the holiday spirit, this week features themes like interconnectedness, family, and impulsive shopping. Let's get into it!

• Carefully consider the source(s) of 'truth' - There are a variety of types of evidence we can use in reaching a conclusion, including first principles (reasoning our way to the answer), anecdotal (storytelling our way to the answer), and experimental (testing our way to the answer). What data we include, and what weight we give it, is up to us. 
• The value of 'what's the worst that can happen?' - Ultimately, the ADA makes an argument for flossing based on first principles, anecdotes from experts, weak experimental data, and a 'do no harm' mindset (i.e., there is no reported damage from flossing, so why not?). The costs of flossing are still subjective (e.g., cost of the floss, mouth pain, and horror from seeing blood pour out of your gums to start the day), but I appreciate the reminder to run the cost / benefit analysis, with a particular focus on downside risk. As I think of other health advice across the spectrum (e.g., sleep, diet, exercise), a lot of it falls into this exact situation where it makes sense in theory, experts have credible stories, there is little experimental data, but it doesn't cost much to try.
• You are an N of 1 unique snowflake (just like Mom said!) - Even with strong experimental data on large groups of people, we have to remember the considerable variance within groups (if you need a reminder, watch a Pharma commercial and listen to the endless warnings of potential side effects). Per Daniel Tammet, "There is no such thing as an average person. They really are guidelines for people to grapple with the unknown, and we can always surprise expectations." So go ahead and get curious, experiment with yourself, and maybe you will be the positive (or negative) outlier that leaves experts scratching their heads in wonder.

• The belief that public health measures are not intended for people like us is widely held by many people like me. Public health, we assume, is for people with less—less education, less-healthy habits, less access to quality health care, less time and money.
• And as with other strongly held beliefs, our fears are dear to us. When we encounter information that contradicts our beliefs, ... we tend to doubt the information, not ourselves.
• What natural has come to mean to us in the context of medicine is pure and safe and benign. But the use of natural as a synonym for good is almost certainly a product of our profound alienation from the natural world.
• Even a modestly informed woman squinting at the rough outlines of a compressed history of medicine can discern that quite a bit of what has passed for science in the past two hundred years, particularly where women are concerned, has not been the product of scientific inquiry so much as it has been the refuse of science re-purposed to support already existing ideologies.
• “Like capital, Dracula is impelled towards a continuous growth,” the literary critic Franco Moretti writes, “an unlimited expansion of his domain: accumulation is inherent in his nature.” What makes Dracula terrifying, Moretti argues, is not that he likes blood or enjoys blood, but that he needs blood.
• “Where there is trust, paternalism is unnecessary,” the philosopher Mark Sagoff writes. “Where there is no trust, it is unconscionable.” And so we are caught in a double bind.
• The health of our bodies always depends on choices other people are making... The point is there’s an illusion of independence... We often manage not to see that we are, as Martin Luther King reminds us, “caught in an inescapable network of mutuality.”
• ...the paradox of feeling responsible for everything and powerless at the same time, a kind of empowered powerlessness.
• When one is investigating scientific evidence, one must consider the full body of information, or survey the full body of water. And if the body is large, this becomes an impossible task for one single person... We do not know alone.
• ...we must somehow square our power with our powerlessness. We can protect our children to some extent. But we cannot make them invulnerable any more than we can make ourselves invulnerable. “Life,” as Donna Haraway writes, “is a window of vulnerability.”

• In four thousand million years of earth history, I am lucky enough to be alive today. In five million species, I was fortunate enough to be born a conscious human being. Among six thousand million people on the planet, I was privileged enough to be born in the country where the word was discovered. In all of the earth’s history, biology and geography, I was born just five years after the moment when, and just two hundred miles from the place where, two members of my own species discovered the structure of DNA and hence uncovered the greatest, simplest and most surprising secret in the universe.
• The age at which the madness will appear depends strictly and implacably on the number of repetitions of the ‘word’ CAG in one place in one gene... The scale is this: if your chromosomes were long enough to stretch around the equator, the difference between health and insanity would be less than one extra inch... We are dealing here with a prophecy of terrifying, cruel and inflexible truth. There are a billion threeletter ‘words’ in your genome. Yet the length of just this one little motif is all that stands between each of us and mental illness.
• Testing without counselling is a recipe for misery... No individual can have fifty per cent of this disease. She either has a one hundred per cent chance or zero chance, and the probability of each is equal. So all that a genetic test does is unpackage the risk and tell her whether her ostensible fifty per cent is actually one hundred per cent or is actually zero.
• One of the dawning realisations of recent decades is just how hard it is to define what is ‘normal’ and what is mutant.
• The conclusion that all these studies converge upon is that about half of your IQ was inherited, and less than a fifth was due to the environment you shared with your siblings – the family. The rest came from the womb, the school and outside influences such as peer groups... But even this is misleading. Not only does your IQ change with age, but so does its heritability. As you grow up and accumulate experiences, the influence of your genes increases.
• Many diseases that are generally thought to be due to environmental conditions, occupation, diet or pure chance are now beginning to be recognised as the side-effects of chronic infections with little known viruses or bacteria.
• The truth is that nobody is in charge. It is the hardest thing for human beings to get used to, but the world is full of intricate, cleverly designed and interconnected systems that do not have control centres...
• Far from being a sentence, the realisation of innate personality is often a release.
• Intelligence requires a judicious mixture of remembering and forgetting.
• There is a world of difference between genetic screening and what the eugenists wanted in their heyday – and it lies in this: genetic screening is about giving private individuals private choices on private criteria. Eugenics was about nationalising that decision to make people breed not for themselves but for the state. It is a distinction frequently overlooked in the rush to define what ‘we’ must allow in the new genetic world.

• Realizing how many different views exist forces you into one of two spots: Arguing with others whose views you think are wrong, or realizing how out of touch you are with people whose experiences have led them to different views. Both are hard to deal with.
• The whole reason markets work are because these gaps in opinion exist. But why do they exist, if we all have roughly the same data? Part of it is because we’ve all had different experiences, and current beliefs depend on past experiences. Which means we’re all pretty much out of touch with one another.
• ...no amount of studying or listening lets you fully understand what it was like to experience these events.
• ...I’ll come closer to understanding your actions by asking what you’ve experienced to make you believe your views, rather than wondering why you don’t agree with mine.

• Imagine the feeling of catching yourself loving yourself without trying.
• Take this one thought, I love myself. Add emotional intensity if you can it deepens the groove faster than anything. Feel the thought. Run it again and again. Feel it. Run it. Whether you believe it or not doesn't matter, just focus on this one thought. Make it your truth.
• ...ultimately, everything is theory. I care about what works. What creates magic in my life.
• Fear strengthens the ego. Love softens it.
• ...it's the things we hold against ourselves that weigh us down more than anything.