Essays

Nine pieces, each carrying the grade of what it rests on.

Every claim below is labelled evidence, suggestion, hypothesis, observation or question, and every piece ends with a note saying where it stops. Where I have been wrong, the mistake is left in rather than deleted.

• Same brain, different day. The first one. Why one person’s output swings when their abilities have not changed.
• Do you vary more than you differ from other people? The best-known number supporting my own argument, and why I stopped citing it.
• How good is the evidence that sleeping on a problem helps? A famous 2004 result, what replication did to it, and a mistake of mine left in.
• Do you have better ideas after sleep, or after time away, or something else? I believed sleep was doing it for years. One study says the variable was wrong.
• Does a job that suits you make you better at it, or just happier? 172 studies. It predicts how you feel about work and barely predicts what you produce.
• You are a poor judge of how much you vary. What people believe about their own steadiness barely matches what measuring them finds.
• What does it mean when they say a trait is 50 percent genetic? The most misread number in public life. It is not a fact about you.
• Your age, your DNA. What do you do about the things you cannot change? Some conditions cannot be assigned. That does not put them outside the question.
• Could a smell be shaping your work without you noticing? The thinnest piece here, on purpose. It marks a hole in the whole project.