Chapter 2: Exercises
Comprehension Check
1. Describe the six stages of the mutation pipeline. For each stage, identify the actor, their primary incentive, and how their incentive distorts the claim.
2. Explain how the marshmallow test finding mutated from Stage 1 (original research) to Stage 6 (audience belief). What specific details were lost or distorted at each stage?
3. What did the Sumner et al. (2014) BMJ study find about university press releases? Why is this finding important for understanding how psychology claims spread?
4. What did the Watts, Duncan, and Quan (2018) replication of the marshmallow test find? How does their finding differ from the popular version of the marshmallow test?
5. Explain why the mutation pipeline is described as an "emergent" product of incentives rather than a conspiracy. What is the difference between these two explanations?
Application
6. Choose a psychology claim you've seen recently on social media or in the news. Try to trace it through the mutation pipeline: - Can you find the original study? (Try Google Scholar) - Can you find the university press release? - Can you find the first news article? - How does the social media version compare to the original? Write up your findings.
7. Find three different news articles covering the same psychology study. Compare: - The headlines (how dramatic? how certain?) - The first paragraph (does it include caveats?) - The last paragraph (does it include limitations?) - Whether the article links to the original paper What patterns do you notice?
8. Write two versions of a press release for the following fictional finding: "In a study of 200 college students, those who took a 10-minute walk before an exam scored 4% higher on average (p = .03, d = 0.22) than those who sat quietly. The researchers note that the effect was only observed for essay-style exams, not multiple choice, and the sample was limited to a single university." - Version A: Accurate and appropriately hedged - Version B: The kind of press release that would generate maximum media coverage Compare the two. What did you add or remove in Version B?
9. Find the abstract of the original Mischel marshmallow test study (or a key follow-up). Read it carefully. Then find a popular article about the marshmallow test. Highlight every claim in the article that is not supported by the abstract. How many did you find?
10. Interview someone you know about a psychology claim they believe. Ask them where they first heard it and whether they've ever seen the original research. Record the conversation (with permission). How many stages of the pipeline do you estimate the claim traveled?
Critical Thinking
11. The chapter argues that the mutation pipeline has "essentially no quality filter." Do you agree? Can you think of any mechanisms — existing or hypothetical — that could serve as quality filters at each stage?
12. The marshmallow test replication found that socioeconomic status explained most of the apparent effect of "self-control." Why might this finding be less viral than the original? What does this tell you about the virality-accuracy trade-off?
13. John Bohannon's chocolate study was designed to be methodologically terrible, yet it was covered by 20+ major outlets. What responsibility does each stage of the pipeline bear for this failure? Who should have caught it?
14. Is there a scenario in which the mutation pipeline produces a more accurate public understanding than the original study? (Hint: consider cases where the researcher's own framing was biased or the caveats were excessive.)
15. Social media platforms could, in theory, add fact-checking labels to psychology claims the same way they do for political claims. Would this work? Why or why not?
Fact-Check Portfolio
16. For each of your 15–20 claims from Chapter 1, note where you first encountered it and estimate how many stages of the mutation pipeline it traveled. You don't need to trace every claim to its source — just estimate. Which of your claims are closest to the original research, and which have traveled the furthest?