Behavioral Science is WEIRD and This Should Concern Us…
When 9 out of 10 of the world's population is underrepresented in behavioral science, are we truly grasping human behavior or just a narrow slice of it?
In 2010, a curious acronym buzzed through the halls of academia: WEIRD. Popularized by researchers Joe Henrich, Steven Heine, and Ara Norenzayan, a troubling observation was unveiled about a bias creeping into behavioral science. This acronym – Western, Educated, Industrialized, Rich, and Democratic – stood for the specific population dominating research within the field.1
The team of researchers found it weird (no pun intended) that while only 12% of the world's population is WEIRD, 96% of samples among top journal articles from 2003 to 2007 were dominated by these backgrounds.2 This means that the 12%'s skewed experiences encompass most behavioral science findings, often assumed to be universal.
This goes for more than just sampling representation. When the team peeked at research beyond the WEIRD bubble, they found something surprising: WEIRD folks, it turns out, are… kind of unusual. From how they perceive the world to how they make moral decisions, WEIRD subjects deviate significantly from the rest of humanity. And yet, these very subjects are the foundation of what we know in behavioral science. This stark difference exposed a hidden flaw: researchers, primarily from Western contexts themselves, had unknowingly assumed their world was everyone else’s.
The worst part? The popularization of this acronym didn’t make things get any better. Another analysis of psychology journals published between 2014 and 2017 revealed that 95% of samples were still drawn from the WEIRD population3 – a mere 1% better than ten years earlier. In yet another audit, Africa, with its 17% global population share, contributed less than 1% to these samples.4 Believe it or not, one in four studies forgo including sample demographics altogether, likely fearing criticism for limited representation.3
Over a decade later, it’s as if the needle hasn’t moved.3 The WEIRD bias continues to cast a long shadow on our understanding of human behavior. Neglecting the voices of the non-WEIRD majority isn't just a bad sampling problem but a complete failure to fully harness behavioral science’s potential. We are missing opportunities to make a difference – or even worse, potentially inflicting harm through misguided interventions.
This article delves into the overreliance on WEIRD populations in behavioral science, exploring actionable steps toward a more inclusive and culturally matched approach to understanding human behavior.
How weird is the WEIRD population?
While "WEIRD" serves as a helpful heuristic, it's important to remember that it's a broad category encompassing many different populations with distinct experiences and perspectives. Just as there are variations within non-WEIRD groups, there's rich diversity within WEIRD groups shaped by factors like ethnicity, socioeconomic status, and geographic location.
For instance, the experience of urban life in Tokyo might share more similarities with bustling New York City than with a remote barrio in the Philippines. Similarly, within diverse societies like India, individual needs and cultural values can vary drastically between rural and urban communities or across distinct religious and ethnic groups.
Some critics have even noted that the acronym is incomplete, not encompassing other dimensions that are equally (if not more) important to note like race.5,6 With this in mind, let's explore just how divergent WEIRD and non-WEIRD societies can be in terms of cognition and behaviors.
It is easy to assume that basic cognitive processes like visual perception are consistent across humans. However, in a study from the 1960s, researchers led by Marshall Segall challenged this idea. Their investigation into the Müller-Lyer illusion revealed striking variations in perception among 15 diverse societies, ranging from American undergraduates to the San foragers of the Kalahari.7,1
References
- Henrich, J., Heine, S. J., & Norenzayan, A. (2010). The weirdest people in the world? SSRN Electronic Journal. https://doi.org/10.2139/ssrn.1601785
- Arnett, J. J. (2008). The neglected 95%: Why American psychology needs to become less American. American Psychologist, 63(7), 602-614. https://doi.org/10.1037/0003-066x.63.7.602
- Apicella, C., Norenzayan, A., & Henrich, J. (2020). Beyond WEIRD: A review of the last decade and a look ahead to the global laboratory of the future. Evolution and Human Behavior, 41(5), 319-329. https://doi.org/10.1016/j.evolhumbehav.2020.07.015
- Thalmayer, A. G., Toscanelli, C., & Arnett, J. J. (2021). The neglected 95% revisited: Is American psychology becoming less American? American Psychologist, 76(1), 116-129. https://doi.org/10.1037/amp0000622
- Wendel, S. (2023). We're WEIRD. In Z. Khan & L. Artavia-Mora (Eds.), Behavioral science for development: Insights and strategies for global impact. Bescy.
- Syed, M. (2021, June 10). WEIRD times: Three reasons to stop using a silly acronym. Get Syeducated. https://getsyeducated.blogspot.com/2021/06/weird-times-three-reasons-to-stop-using.html
- Segall, M. H., Campbell, D. T., & Herskovits, M. J. (1963). Cultural Differences in the Perception of Geometric Illusions. Science, 139(3556), 769–771. doi:10.1126/science.139.3556.769
- Thomas, C. C., & Markus, H. R. (2023). Enculturating the science of international development: Beyond the WEIRD independent paradigm. Journal of Cross-Cultural Psychology, 54(2), 195-214. https://doi.org/10.1177/00220221221128211
- Kizilcec, R. F., & Cohen, G. L. (2017). Eight-minute self-regulation intervention raises educational attainment at scale in individualist but not collectivist cultures. Proceedings of the National Academy of Sciences, 114(17), 4348–4353. doi:10.1073/pnas.1611898114
About the Author
Celestine Rosales
Celestine is a Junior Research Analyst at The Decision Lab. She is a researcher with a passion for understanding human behavior and using that knowledge to make a positive impact on the world. She is currently pursuing her Master's degree in Social Psychology, where she focuses on issues of social justice and morality. She also holds a Bachelor's degree in Psychology. Before joining TDL, Celestine worked as a UX Researcher at a conversion rate optimization company, where she collaborated with a variety of B2B and SaaS clients to help them improve their websites. She also participated in an all-women cohort of scholars trained to do data analytics. Outside of work, Celestine enjoys taking long walks, listening to podcasts, and trying new things.
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