The Replication Crisis in Psychology

Every prior chapter of this course has surfaced its own individual case of a famous finding not holding up as well as its popular reputation suggests. This chapter steps back and names the pattern directly: a real, field-wide "replication crisis" that psychology has spent the last decade actively confronting.

The Field-Wide Evidence — Already Covered Elsewhere on This Site

This site's own Scientific Methodology course already covers the single most important piece of real evidence behind this crisis in depth — the 2015 Open Science Collaboration reproducibility study, which attempted to replicate 100 published psychology studies and found only around a third produced a statistically significant effect the second time, with surviving effect sizes roughly half their original size. Rather than repeat that material here, this chapter points to it directly: see Scientific Methodology, Chapter 6 ("Reproducibility"), and builds on it with a case specific to psychology's own popular reach.

Amy Cuddy's "Power Posing": A Real, Especially Public Case

In 2010, Dana Carney, Amy Cuddy, and Andy Yap published a study with 42 participants claiming that holding an expansive, "powerful" physical pose for just two minutes produced real measurable changes — increased testosterone, decreased cortisol, and greater self-reported risk tolerance. The idea that a simple bodily posture could genuinely shift a person's own hormones and confidence was enormously appealing, and Cuddy's 2012 TED talk presenting it became one of the platform's most-watched talks ever, reaching roughly 47 million views by 2017.

This case is worth sitting with specifically because of what makes it different from several of this course's other examples. Zimbardo (Chapter 6) still stands by his own original study today, disputing Le Texier's critique. Mischel's marshmallow test (Chapter 7) was weakened, not eliminated, by later replication. Power posing is a genuinely rarer case: an original author of the finding publicly repudiating her own earlier conclusion, in the full glare of the finding's own massive popular reach.

Why This Keeps Happening

What the Field Has Actually Done About It

This isn't a story of psychology quietly ignoring its own problem. The 2015 Open Science Collaboration project (Scientific Methodology, Chapter 6) was itself the field's own large-scale, coordinated response — a deliberate, public effort to measure the real scale of the problem rather than look away from it. Pre-registration (committing to a study's own hypotheses and analysis plan before collecting data, also covered in Scientific Methodology's own Chapter 8) has become far more common specifically because of cases like this one, precisely to prevent a positive-sounding but ultimately fragile result from being published, popularized, and only years later quietly walked back.

Hands-On Exercises