18. Overton Window: You can control thought without limiting speech. You can do it by defining the limits of acceptable thought while allowing for lively debate within these barriers. For example, Fox News and MSNBC set limits on what political thoughts they consider acceptable, but in the grand scheme of things, they’re both fairly conventional. The political spectrum stretches far beyond the ideas they entertain, but ideas outside their limits are shunned.
19. Planck’s Principle: Science doesn’t progress because people change their views. Rather, each new generation of scientists has different views. As old generations pass away, new ideas are accepted and the scientific consensus changes.
20. Bike-Shed Effect: A group of people working on a project will fight over the most trivial ideas. They’ll ignore what’s complicated. They’ll focus too much on easy-to-understand ideas at the expense of important, but hard to talk about ideas. For example, instead of approving plans for a complicated spaceship, the team would argue over the color of the astronaut's uniforms.
21. Table Selection: This idea comes from poker, where you’re advised to choose your opponents carefully. That means you shouldn’t compete against the best people. You don’t need to get good at doing difficult things if you get good at avoiding difficult things. If you want to win, pick an easy table and nail your execution.
22. Goodhart’s Law: When a measure becomes a target, it ceases to be a good measure. One hospital took too long to admit patients so a penalty was given for 4+ hour wait times. In response, ambulance drivers were asked to slow down so they could shorten wait times.
23. Gall’s Law: A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over with a working simple system.
24. Hock Principle: Simple, clear purpose and principles give rise to complex and intelligent behavior. Complex rules and regulations give rise to simple and stupid behavior.
25. Parkinson’s Law: Work expands to fill the time available. People don’t want to look like they’re lazy, so they find extra tasks to tackle, even if they’re trivial. If you have six months to complete a project, it will take six months to complete. Set deadlines accordingly.
26. The Second Law of Thermodynamics: The world tends towards disorder. That’s why your room becomes messier and messier over time. It’s also why an engine converts only ~35% of its energy into useful work. Time moves towards increasing one direction: increasing entropy.
27. The Paradox of Specificity: Focus isn’t as constraining as it seems. In the age of the Internet, when everybody has Google search and personalized social media feeds, differentiation is free marketing. The more specific your goal, the more opportunities you’ll create for yourself. Narrowing your aperture can expand your horizons.
28. Emergence: When things interact, they often birth new, unpredictable forms. Therefore, the sum total of a system is more than its component parts. As a system evolves, its structure can transform — just like how water becomes cold water until it turns into ice.
29. Occam's Razor: If there are multiple explanations for why something happened and they are equally persuasive, assume the simplest one is true. In the search for truth, remove unnecessary assumptions. Trust the lowest-complexity answer.
30. Hickam’s Dictum: The opposite of Occam’s Razor. In a complex system, problems usually have more than one cause. For example, in medicine, people can have many diseases at the same time.
31. Hormesis: A low dose of something can have the opposite effect of a high dose. A little bit of stress wakes you up, but a lot of stress is bad for you. Lifting weights for 30 minutes per day is good for you, but lifting weights for 6 hours per day will destroy your muscles. Stress yourself, but not too much.
32. Robustness Principle: Be conservative in what you do, be liberal in what you accept from others. It’s a design guideline for software and a good rule for life: Hold yourself to a higher standard than you hold others to.
33. Legibility: We are blind to what we cannot measure. Not everything that counts can be measured, and not everything that can be measured counts. But people manage what they can measure, so society repeats the same mistakes.
34. Horseshoe Theory: Extreme opposites tend to look the same. For example, a far-right movement and a far-left movement can be equally violent or desire a similar outcome. People on both sides are more similar to each other than they are to people in the center.
35. Availability Cascade: A self-reinforcing cycle that creates collective beliefs. An idea will gain traction once it enters the mainstream, which triggers a chain reaction, which causes lots of people to adopt it not because it’s true but because it’s popular.
36. Creativity Begins at the Edge: Change starts away from the spotlight. Then, it moves towards the center. That’s why the most interesting ideas at a conference never come from the main stage. They come from the hallways and the bar after sunset
37. The Copernican Principle: The more we learn about astronomy, the less it seems that earth is special. It's a small part of the universe, and each human is a small part of the earth. We are all spinning through the solar system — nowhere near the beginning or end of time.
38. Personal Monopoly: Corporations reward conformity, but the Internet rewards people who are unique. If you work in a creative field, strive to be the only person who does what you do. Find your own style, then run with it. Create intellectual real estate for yourself.
39. The Paradox of Consensus: Under ancient Jewish law, if a suspect was found guilty by every judge, they were deemed innocent. Too much agreement implied a systemic error in the judicial process. Unanimous agreement sometimes leads to bad decisions.
40. Penny Problem Gap: Economists assume demand is linear, but people’s behavior totally changes once an action costs money. If the inventors of the Internet had known about it, spam wouldn’t be such a problem. If sending an email cost you $0.001, there’d be way less spam.
41. The Invisible Hand: Markets aggregate knowledge. Rising prices signal falling supply or increased demand, which incentivizes an increase in production. The opposite is true for falling prices. Prices are a signal wrapped in an incentive.
42. Base Rate: The average outcome for an event over time. They're like batting averages for life, and they work best with big sample sizes. For example, if you’re starting a business, avoid the restaurant business where margins are low and competition is high.
43. Circle of Competence: Define the limits of your knowledge. Hint: the limits are smaller than you think. That’s because being an expert in one area doesn’t make you an expert in anything else. Be clear about what you know and don’t know.
44. Convexity: If you want to be lucky, look for opportunities with big upsides and low downsides. In addition to increased optionality, your errors will benefit you more than they harm you. Convex payoffs let you tinker your way to success and innovation.
45. The Go-For-It Window: Large gaps between accelerating technologies and stagnating social norms create lucrative new business opportunities. But they are only available for a short time when people can capitalize on the difference between the real and perceived state of the world. For example, 2007 was the perfect time to launch the iPhone, but Google Glasses launched too early.
46. Via Negativa: When we have a problem, our natural instinct is to add a new habit or purchase a fix. But sometimes, you can improve your life by taking things away. For example, the foods you avoid are more important than the foods you eat.
47. The Medium Is the Message: We pay too much attention to what is being said. But the medium of communication is more impactful. For example, the Internet’s impact on humanity has a bigger influence than anything that’s said on the Internet.
48. Resource Curse: Countries with an abundance of natural resources such as diamonds and fossil fuels tend to have less economic growth and worse development than countries with fewer natural resources.
49. The Paradox of Abundance: The average quality of information is getting worse and worse. But the best stuff is getting better and better. Markets of abundance are simultaneously bad for the median consumer but good for conscious consumers.
50. The Map Is Not the Territory: Reality will never match the elegance of theory. All models have inconsistencies, but some are still useful. Some maps are useful because they’re inaccurate. If you want to find an edge, look for what the map leaves out.
51. Baker’s Dozen: The key to good hospitality is to delight your guests with an unexpected gift. If you run a hotel, leave a chocolate on the bed. If you run a bakery, give your customers one extra bagel. If you write a tweetstorm, share an extra idea.