Psychology
How the mind actually makes decisions, processes experience, and constructs the story it tells about itself.
Psychology is not self-help. It is the attempt to understand how minds actually work: not how we wish they worked or assume they work, but what the evidence says happens when a person perceives, decides, feels, and remembers.
The Gap Between Thinking and Thinking About Thinking
We are not reliable observers of our own mental processes. We explain our decisions after the fact and mistake the explanation for the cause. We notice our emotions when they are strong and ignore them when they are shaping our behavior most invisibly. We believe we are reasoning when we are often rationalizing.
This is not a flaw to be corrected. It is the architecture of a system that evolved to act quickly rather than accurately. Understanding that architecture (where the fast automatic system takes over, where deliberate reasoning actually helps, and where the two together produce systematic errors) changes how you read your own behavior and the behavior of the people around you.
What Kahneman and Others Actually Found
The dual-process research tradition (System 1 and System 2, fast and slow thinking, heuristics and biases) is often summarized in ways that flatten its findings. The popular version is: slow down and you will make better decisions. The actual finding is more interesting and more troubling: deliberate reasoning does not always override intuition, and sometimes it should not. The cases where System 1 is right and System 2 misleads you are as important as the cases where the reverse is true.
The essays in this chapter try to stay close to what the research actually says, rather than the cleaned-up version that fits on a slide.
Psychology in Product and Systems Design
The way humans process information, form habits, respond to loss and gain, and make decisions under uncertainty is not just interesting to therapists and researchers. It is directly relevant to anyone designing a product, running a team, or trying to change their own behavior. These connections are worth examining carefully, not to manipulate but to build things that work with human psychology rather than against it.
13 essays in this chapter
- Does Social Proof Actually Work? What 8.57 Million Households Show Social proof works, but not the way product teams think. Opower's trials across 8.57M households averaged 1-2%, and for some users the effect ran backwards.
- Cognitive Load in UX: What the Research Actually Says What the research on cognitive load actually says about the 7±2 rule, the jam study and the three-click rule, and why design keeps citing all three wrong.
- Behavioral Economics in B2B Sales: The Patterns That Actually Close Deals Behavioral economics in B2B sales isn't about persuasion. 2.5M recorded calls show most deals die from buyer fear of blame, and urgency makes it worse.
- Why People Don't Cancel Unused Subscriptions: The Endowment Effect in Software Why people don't cancel unused subscriptions: the endowment effect keeps users paying for software they never open. Field notes on what that dormant retention costs the people who build it.
- Psychology of Waiting: Why Perceived Wait Time Wins Perceived wait time, not clock time, decides how long a wait feels. What the research shows, and why hold music beat your skeleton screens in 1962.
- Base Rate Neglect in Product: What Google Flu Trends Got Wrong Google Flu Trends over-predicted flu in 100 of 108 weeks. Harvard-trained doctors failed the same test. What base rate neglect is, why the algorithm failed, and how the same bias is built into your dashboards.
- Does Fake Scarcity Marketing Still Work If You Know It's Fake? Fake scarcity marketing keeps working even after regulators expose it as staged. Here's the research on why knowing the countdown is fake doesn't stop you from buying.
- Paradox of Choice in SaaS Product Design: Why More Pricing Tiers Convert Worse Paradox of choice product design keeps failing: why more pricing tiers and toggles tank conversion, from the jam study to Pendo's 2019 data.
- How Long Does It Take to Form a Habit? What the Science Actually Says The research says 66 days, not 21, with a range from 18 to 254. Here's where the 21-day rule came from, and why the real number reveals something most habit advice gets backwards.
- Status Games: Why People Buy Things They Do Not Need and What That Means for Builders Status psychology and buying behavior explain why cheaper, better products lose. And why 'just compete on value' is the advice that's quietly bankrupting you.
- Commitment and Consistency: Why Small Yeses Lead to Big Ones, and When They Backfire I spent years treating commitment and consistency as a Cialdini sales trick. Here's the study that proved I had the mechanism backwards, and where it curdles into sunk cost.
- Decision Fatigue Is Real and Your Product Is Probably Making It Worse Decision fatigue in product design isn't a myth; it's a measurable pattern companies exploit. Here's the research and the system behind it.
- Why Do Product Redesigns Fail? What Snapchat and New Coke Reveal About System 1 Why do product redesigns fail even when the data says they'll work? Snapchat's 2018 redesign and Coca-Cola's New Coke show it's the brain's fast, automatic System 1, not System 2, that decides.