Simpson's paradox in psychological science: a practical guide
Open Access
- 1 January 2013
- journal article
- review article
- Published by Frontiers Media SA in Frontiers in Psychology
- Vol. 4, 513
- https://doi.org/10.3389/fpsyg.2013.00513
Abstract
The direction of an association at the population-level may be reversed within the subgroups comprising that population—a striking observation called Simpson’s paradox. When facing this pattern, psychologists often view it as anomalous. Here, we argue that Simpson’s paradox is more common than conventionally thought, and typically results in incorrect interpretations – potentially with harmful consequences. We support this claim by drawing on empirical results from cognitive neuroscience, behavior genetics, psychopathology, personality psychology, educational psychology, intelligence research, and simulation studies. We show that Simpson’s Paradox is most likely to occur when inferences are drawn across different levels of explanation (e.g., from populations to subgroups, or subgroups to individuals). We propose a set of statistical markers indicative of the paradox, and offer psychometric solutions for dealing with the paradox when encountered—including a toolbox in R for detecting Simpson’s Paradox. We show that explicit modeling of situations in which the paradox might occur not only prevents incorrect interpretations of data, but also results in a deeper understanding of what data tell us about the world.Keywords
This publication has 46 references indexed in Scilit:
- The Sensory Components of High-Capacity Iconic Memory and Visual Working MemoryFrontiers in Psychology, 2012
- Willingness to Share Research Data Is Related to the Strength of the Evidence and the Quality of Reporting of Statistical ResultsPLOS ONE, 2011
- The Hot (Invisible?) Hand: Can Time Sequence Patterns of Success/Failure in Sports Be Modeled as Repeated Random Independent Trials?PLOS ONE, 2011
- The Simpson's paradox unraveledInternational Journal of Epidemiology, 2011
- Cultural differences are not always reducible to individual differencesProceedings of the National Academy of Sciences of the United States of America, 2010
- Childhood Mental Ability and Adult Alcohol Intake and Alcohol Problems: The 1970 British Cohort StudyAmerican Journal of Public Health, 2008
- Simpson's paradox visualized: The example of the Rosiglitazone meta-analysisBMC Medical Research Methodology, 2008
- Simpson's Paradox, Lord's Paradox, and Suppression Effects are the same phenomenon – the reversal paradoxEmerging Themes in Epidemiology, 2008
- Mediation AnalysisAnnual Review of Psychology, 2007
- Normative and Descriptive Analyses of Simpson's Paradox in Decision MakingOrganizational Behavior and Human Decision Processes, 2001