Chapter 4: Exercises — How Our Brains Misread Luck

These exercises progress from recall and comprehension to analysis, application, and original research design. Work at your own pace. Questions marked with a star (*) are suitable for group discussion.

Level 1: Recall and Comprehension

1. Define apophenia in your own words. Give one example from daily life that was not mentioned in the chapter.

2. What is the difference between apophenia and pareidolia? Which is the broader category?

3. The chapter describes the hot hand fallacy. In one sentence, state what the hot hand fallacy claims.

4. Name the three authors of the original 1985 hot hand paper and the two authors of the 2016 reanalysis.

5. What is the gambler's fallacy? How is it the "mirror image" of the hot hand fallacy?

6. In Marcus's conversation with Dr. Yuki, she calculates the probability of winning four games in a row for a player with a 68% win rate. What did she find, and what conclusion did they draw from it?

7. Define self-serving attribution bias and the fundamental attribution error. What makes them "paired" errors?

8. What is variable ratio reinforcement? Give one example from gambling and one from social media.

9. What did Baruch Fischhoff and Ruth Beyth find in their 1975 study on hindsight bias?

10. According to the chapter, why does knowing about a cognitive bias not reliably eliminate its effect on decision-making?

Level 2: Comprehension and Application

11. * A friend tells you: "I've been flipping this coin and I've gotten heads seven times in a row. Tails is definitely due next." Which cognitive bias are they exhibiting, and how would you explain the error to them?

12. Nadia believes that using a specific Instagram filter causes her videos to perform better. Describe how confirmation bias would cause this belief to persist even if the filter has no actual effect.

13. Think about a success or achievement in your own life. Apply the self-serving attribution bias framework: what aspects of the success might you be crediting to internal factors that were actually partly external or lucky?

14. * Priya is rejected from a job and thinks, "They probably had an internal candidate." When a friend gets a similar job, Priya thinks, "She's lucky — she knows people." Identify the attribution errors in Priya's thinking. How might both explanations be partially true simultaneously?

15. Marcus wins four games in a row and develops new beliefs about his sleep schedule, his playlist, and his hoodie. Which cognitive biases are operating in this scenario? Identify at least three, and describe how each contributes to his conclusions.

16. * Explain how hindsight bias makes studying lucky events systematically difficult. What would a researcher have to do to study a lucky event without hindsight contaminating the data?

Level 3: Analysis and Synthesis

17. The chapter states that "the feeling of having detected a pattern is the same whether the pattern is real or illusory." If this is true, what practical tool or practice could a person use to distinguish real patterns from illusory ones? Design a brief decision procedure.

18. Compare and contrast the gambler's fallacy and the hot hand fallacy in terms of: (a) what triggers each, (b) what the person believes will happen next, and (c) what the research says about accuracy. Use a table or structured comparison.

19. The 2016 Miller and Sanjurjo paper found a statistical error in the original 1985 Gilovich et al. study. Explain in your own words what that statistical error was (the small-sample bias in finite sequences) and why it mattered for the conclusion about hot hands.

20. * "Even scientists are subject to the biases they study." The chapter makes this claim with reference to the hot hand research. Do you find this claim disturbing, reassuring, or both? What does it imply about how we should evaluate scientific research on cognitive bias?

21. Design a simple study — using only a notepad and one week of observations — that would allow you to test whether a specific "lucky ritual" you observe (your own or a friend's) has any real statistical effect on outcomes. What would the data need to look like to confirm or disconfirm the ritual's effectiveness?

22. The chapter describes how social media algorithms reward content that exploits human cognitive biases. Does this mean that content creators who understand cognitive bias have an unfair advantage? Or is exploiting bias the legitimate craft of engaging communication? Make an argument for a clear position.

Level 4: Evaluation and Critical Thinking

23. * The Miller and Sanjurjo reanalysis suggests that the hot hand may be real, at least in some domains and with small effect sizes. Does this mean the original "hot hand is a fallacy" conclusion was wrong, or incomplete, or premature? These three words have importantly different meanings — defend your choice.

24. The chapter argues that "awareness of a bias does not reliably reduce its effect." If this is true, what is the practical value of learning about cognitive biases? Write a four-sentence argument for why this textbook chapter is worth reading, given this limitation.

25. Consider two students: Student A learns about the hot hand fallacy and decides, "Since streaks are probably random, there's no point analyzing performance patterns." Student B learns about it and decides, "I should analyze my performance patterns with much more data and skepticism than I would have before." Which student has better understood the chapter's argument? Why might Student A's conclusion, while emotionally understandable, be wrong?

26. * Priya is on a three-month job search. She has applied to 60 positions and gotten three interviews. One of her friends, who she considers less qualified, just got a job offer. How many cognitive biases is Priya likely to be deploying in her thinking about her own situation and her friend's outcome? List each bias, describe how it would manifest in her specific situation, and then describe what information would actually be needed to evaluate the situation accurately.

Level 5: Research and Creative Challenge

27. The Streak Journal. For one week, keep a detailed log of any "streak" you notice in your own life — academic, athletic, creative, social, or even just mood-based. At the end of each day, record: (a) what the streak was, (b) what internal explanation your brain offered, (c) what external explanation is also possible, and (d) what data would distinguish the two. At the end of the week, write a 400-word analysis of what you found.

28. Recreating the Hot Hand Data. With a group, run the following experiment: have one person flip a coin 100 times and record each result as H or T. Then count: what is the proportion of heads on the flip immediately following a streak of three heads? If the hot hand logic were correct, this proportion should be higher than 50%. If the gambler's fallacy logic were correct, it should be lower. What do you find? Run the exercise three times with three different sequences and pool your results.

29. Social Media Confirmation Bias Audit. Choose one belief you have about what makes content successful on a social media platform (this can be your own or a platform you use as a consumer). Design a 30-day systematic audit: what data would you collect? How would you operationalize "success"? What constitutes a valid test of your hypothesis? Write the research design in two pages, including: hypothesis, method, data collection, and how you would determine if you were wrong.

30. The Attribution Bias Flip. Think of three outcomes in your life — one success, one failure, one neutral event. For each, write two explanations: first, the explanation your brain naturally offers (which may be self-serving). Second, the most credible explanation that prioritizes the opposite attribution (external for success, internal for failure). Then write a third paragraph: what does the truth probably look like, holding both explanations simultaneously?

Answers to selected questions appear in Appendix B: Answers to Selected Exercises.