Normal Curves is a podcast about sexy science & serious statistics.
Does the temperature of your coffee six months ago really predict whether you feel gassy today? This week we dissect a new nutrition survey study on hot and cold beverage habits that claims to connect drink temperature with gut symptoms, anxiety, and more—despite relying on year-old memories and a blizzard of statistical tests. It’s the perfect case study for our Holiday Survival Guide Part 2, where we teach you how to talk with Uncle Joe at the dinner table about one of the most common—and most fraught—study designs in science: cross-sectional surveys. We walk through our easy checklist for making sense of results, show how recall bias and measurement error can skew the story, and reacquaint you with nonmonogamous Multiple-Testing Dude, who’s been very busy in this dataset. A friendly, practical guide to spotting when researchers are just torturing the data until it confesses.
Statistical topics
Methodological morals
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
Does a little alcohol really make you speak a foreign language better? This week we unpack a quirky randomized trial that tested Dutch pronunciation after a modest buzz—and came to the opposite conclusion the researchers expected. We use it as the perfect holiday case study: instead of arguing with Uncle Joe at the dinner table, we’ll show you how to pull apart a scientific headline using a friendly, practical checklist anyone can learn. Along the way we stress-test the study’s claims, take a quick detour into what a .04% buzz actually looks like, and run our own before-and-after experiment with two brave science journalists at the ScienceWriters2025 conference in Chicago. A holiday survival guide with vodka tonics, statistical sleuthing, and a few surprisingly smooth French phrases.
Statistical topics
Methodological morals
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
What do chickenpox and shingles have to do with your brain? This week, we dig into two 2025 headline-grabbing studies that link the shingles shot to lower dementia rates. We start in Wales, where a birthday cutoff turned into the perfect natural experiment, and end in the U.S. with a multi-million-person megastudy. Featuring bias-variance Goldilockses, Fozzy-the-Bear regression discontinuities, a Barbie-versus-Oppenheimer showdown for propensity scores – and the hottest rebrand of inverse-probability weighting you’ll ever hear.
Statistical topics
Methodological morals
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
What if a haunted house makes your date look hotter? This week we dive into the infamous Scary Bridge Study — the 1970s classic that launched a thousand pop-psych takes on fear and lust. It’s the one with the swaying bridge, pretty “research assistant,” and phone number scrawled on torn paper. The study became legend, but how sturdy were its stats? We retrace the design, redo the numbers, and see how many math errors it takes to sway a suspension bridge. Along the way we find an erotic-fiction writing exercise, Adventure Dudes choosing their own experimental groups, and snarky replicators who tried (and failed) to make fear sexy again. We wrap with what the latest research says about when fear really does boost attraction — and when it backfires spectacularly. A Halloween story of danger, desire, and unconscious sexual drive.
This episode has a video version! https://www.youtube.com/watch?v=2coWoS_3460
Statistical topics
Methodological morals
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
Ultramarathoners push their bodies to the limit, but can a giant pre-race dose of vitamin D really keep their bones from breaking down? In this episode, we dig into a trial that tested this claim – and found a statistical endurance event of its own: six highly interchangeable papers sliced from one small study. Expect missing runners, recycled figures, and a peer-review that reads like stand-up comedy, plus a quick lesson in using degrees of freedom as your statistical breadcrumbs.
Statistical topics
Methodological morals
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
00:00 Intro & claim of the episode
00:44 Runner’s World headline: Vitamin D for ultramarathoners
02:03 Kristin’s connection to running and vitamin D skepticism
03:32 Ultramarathon world—Regina’s stories and Death Valley race
06:29 What ultramarathons do to your bones
08:02 Boy story: four stress fractures in one race
10:00 Study design—40 male runners in Poland
11:33 Missing flow diagram and violated intention-to-treat
13:02 The intervention: 150,000 IU megadose
15:09 Blinding details and missing randomization info
17:13 Measuring bone biomarkers—no primary outcome specified
19:12 The wrong clinicaltrials.gov registration
20:35 Discovery of six papers from one dataset (salami slicing)
23:02 Why salami slicing misleads readers
25:42 Inconsistent reporting across papers
29:11 Changing inclusion criteria and sloppy methods
31:06 Typos, Polish notes, and misnumbered references
32:39 Peer review comedy gold—“Please define vitamin D”
36:06 Reviewer laziness and p-hacking admission
39:13 Results: implausible bone growth mid-race
41:16 Degrees of freedom sleuthing reveals hidden sample sizes
47:07 Open data? Kristin emails the authors
48:42 Lessons from Kristin’s own ultramarathon dataset
51:22 Fishing expeditions and misuse of parametric tests
53:07 Strength of evidence: one smooch each
54:44 Methodologic morals—Mad Libs Science & degrees of freedom breadcrumbs
56:12 Anyone can spot red flags—trust your eyes
57:34 Outro: skip the vitamin D shot before your next run
P-values show up in almost every scientific paper, yet they’re one of the most misunderstood ideas in statistics. In this episode, we break from our usual journal-club format to unpack what a p-value really is, why researchers have fought about it for a century, and how that famous 0.05 cutoff became enshrined in science. Along the way, we share stories from our own papers—from a Nature feature that helped reshape the debate to a statistical sleuthing project that uncovered a faulty method in sports science. The result: a behind-the-scenes look at how one statistical tool has shaped the culture of science itself.
Statistical topics
Methodological morals
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
Exercise has long been hailed as cancer-fighting magic, but is there hard evidence behind the hype? In this episode, we tackle the CHALLENGE trial, a large phase III study of colon cancer patients that tested whether prescribed exercise could improve cancer-free survival. We translate clinical jargon into plain English, show why ratio statistics make splashy headlines while absolute differences tell the real story, and take a detour into why statisticians think survival analysis is downright sexy. And we even bring in a classic reality show to make sense of the numbers.
Statistical topics
Methodological morals
References
Thanks
Thanks to Caitlin Goodrich for the episode topic tip!
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
Are we all secretly ageist when it comes to dating? We put the stereotype that older men prefer younger women under the microscope using data from thousands of blind dates. What we found surprised us: the “age penalty” was real but microscopic, women wanted younger partners too, and hard age cutoffs weren’t so hard after all. Along the way, we unpack statistical significance versus practical importance, play with the infamous “half your age plus seven” rule, and imagine what it would take for love to die out… somewhere around age 628.
Statistical topics
Methodological morals
Show Notes Technical Appendix (with step-by-step explanations)
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
ChatGPT is melting our brainpower, killing creativity, and making us soulless — or so the headlines imply. We dig into the study behind the claims, starting with quirky bar charts and mysterious sample sizes, then winding through hairball-like brain diagrams and tens of thousands of statistical tests. Our statistical sleuthing leaves us with questions, not just about the results, but about whether this was science’s version of a first date that looked better on paper.
Statistical topics
Methodological morals
Kristin and Regina’s online courses:
Programs that we teach in:
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
Can correcting misinformation make it worse? The “backfire effect” claims that debunking myths can actually make false beliefs stronger. We dig into the evidence — from ghost studies to headline-making experiments — to see if this psychological plot twist really holds up. Along the way, we unpack interaction effects, randomization red flags, and what happens when bad citations take on a life of their own. Plus: dirty talk analogies, statistical sleuthing, and why “familiarity” might be your brain’s sneakiest trick.
Statistical topics
Unpublished "Ghost Paper"
Citations
Kristin and Regina’s online courses:
Programs that we teach in:
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com
Loyal, funny, hot — you’ve probably got a wish list for your dream partner. But does checking all your boxes actually lead to happily ever after? In this episode, we dive into a massive global study that put the “ideal partner” hypothesis to the test. Do people really know what they want, and does getting it actually make them happier? We explore surprising statistical insights from over 10,000 romantics in 43 countries, from mean-centering and interaction effects to the good-catch confounder. Along the way, we dig into dessert metaphors, partner boat-count regression models, and the one trait that people say doesn’t matter — but secretly makes them happiest.
Statistical topics
Methodological morals
“Good science bares it all.”
“When the world isn't one size fits all, don't fit just one line; use random slopes and intercepts.”
References
Kristin and Regina’s online courses:
Demystifying Data: A Modern Approach to Statistical Understanding
Clinical Trials: Design, Strategy, and Analysis
Medical Statistics Certificate Program
Epidemiology and Clinical Research Graduate Certificate Program
Programs that we teach in:
Epidemiology and Clinical Research Graduate Certificate Program
Find us on:
Kristin - LinkedIn & Twitter/X
Regina - LinkedIn & ReginaNuzzo.com