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Behavioral Science is WEIRD and This Should Concern Us…

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Feb 01, 2024

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 behavior.

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

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The Müller-Lyer illusion is a visual phenomenon where two lines of the same length appear to be different because of the arrowheads facing opposite directions at their ends. American undergraduates demonstrated great susceptibility to the illusion. Meanwhile, for the participants from small-scale societies in Africa and the Philippines, the illusion was less effective.

When tested using other visual illusions like Sander-Parallelogram and Horizontal-Vertical Illusions, the findings were the same. This contrast led researchers to suggest that visual perception is affected by cultural influences, such as growing up in environments that promote different "visual habits." For example, exposure to more rectangular environments in Western societies might lead them to interpret angles differently, influencing their perception so that they are more likely to fall for the Müller-Lyer illusion. 

On the behavioral front, researchers have found a similar pattern from the endowment effect, where people tend to overvalue their possessions. Apicella and colleagues investigated this bias in the Hadza, a Tanzanian hunter-gatherer society with varying degrees of market exposure. Intriguingly, Hadza who lived in areas with an increased exposure to shops and trade exhibited the endowment effect. Meanwhile, those in remote communities without regular market interaction did not, suggesting this effect is not universal. This challenges existing beliefs about the effect's innate origins, hinting that it might be more influenced by cultural factors such as communal ownership norms seen in hunter-gatherer societies. Additionally, it can be modulated by shifting mindsets towards individualism or collectivism, as evidenced by studies involving students of diverse cultural backgrounds.3

These insights into visual illusions and the endowment effect are just a few examples highlighting the differences between WEIRD and non-WEIRD populations. This divergence extends to various domains, including moral judgments, economic preferences, and social behaviors in children.3 It is crucial to underscore that the difference is cultural: rooted in each group’s unique values, norms, and experiences. Understanding these cultural differences has profound implications for applying psychological research to real-world situations, emphasizing the need to expand our understanding of human behavior outside the WEIRD bubble.

Independent and interdependent agency in international development

Let’s consider how the WEIRD problem applies in real-world situations. Why do some initiatives struggle to impact diverse communities effectively? Often, we attribute a program's success or failure to logistical, historical, political, or economic challenges, particularly in low-income areas. However, psychologists Catherine Thomas and Hazel Rose Markus provide an alternative explanation: we design initiatives neglecting to account for the interdependent model of agency.8 

What’s that, you ask? In several contemporary low-income regions, particularly in the Global South, the concept of one’s identity significantly differs from the Western perspective. These cultures often perceive an individual not as an autonomous, isolated unit but as an integral part of a larger social entity. This is called “interdependence.” Here, a person's identity is deeply intertwined with their extended family, community, or village, suggesting a collective sense of self.

Compare that to many developmental initiatives led by WEIRD societies that predominantly adopt an independent model of agency. This approach focuses primarily on the individual’s personal aspirations, needs, rights, and well-being without regarding anyone else. Such a perspective, albeit well-intentioned, may inadvertently clash or be a cultural mismatch with the deeply rooted norms of interdependent communities who prioritize collective values over individualistic ones.

For instance, in a study involving thousands of students in India, a motivational technique involving visualizing personal goals and aspirations, although effective in the United States, did not enhance academic engagement.8,9 The reason? Cultural differences. In collectivist countries like India, being there for family and friends and meeting social expectations often trumps individual goals. In fact, Indian students said they were motivated to do well in school mainly to avoid disappointing their loved ones, a sentiment less common among American students.

In another study in Niger, researchers tried two different ways to help low-income, rural women improve their financial circumstances. The first group was shown a film about women succeeding in business by setting personal intentions with their independence in mind. Afterward, the participants worked on setting and planning their own goals. Meanwhile, the second group also watched a film where this time women succeeded because of the advice and help gained from their community. This group was then asked to create community-oriented goals, framing success as something that could help their family and village. A year later, only the women who focused on community goals saw real improvements, like more food and better business. This suggests that in Niger, working together and supporting each other can lead to better economic outcomes.8

The problem is clear: persisting with the WEIRD lens risks perpetuating harmful mismatches. By recognizing the diverse models of agency at play and adapting to the interdependent dynamics within non-WEIRD groups, initiatives can become more culturally aligned and effective. This can help to bridge the gap between WEIRD-led development strategies and the realities of global communities.

Moving beyond the WEIRD

Truly grasping the complexities of human behavior calls for a concerted effort to embrace the full spectrum of global experiences and perspectives. But how do we actually translate these ideals into actionable steps? Here are seven non-exhaustive ideas for moving beyond the WEIRD bubble in behavioral science.

  1. Partnering with Local Champions: Partnering with local researchers and communities within non-WEIRD contexts allows us to gain first-hand insights into their lived experiences. This should ensure that our research, throughout the scientific process, aligns with their values and priorities, ultimately leading to more impactful outcomes. Such partnerships enrich our understanding and help integrate interdependent perspectives into science, fostering mutual respect and a more comprehensive understanding of human behavior.
  2. Decolonizing the Research Landscape: Decolonization involves recognizing and valuing the knowledge systems and research methodologies inherent to non-WEIRD communities. These communities often hold valuable insights and solutions based on their unique cultural and social contexts. By nurturing an inclusive research landscape that embraces the interdependent nature of knowledge production, we can move beyond the limitations of the WEIRD perspective and tap into the collective wisdom of diverse societies.
  3. Championing Language, Publication, and Researcher Diversity: Alongside supporting research in non-WEIRD languages and diverse academic outlets, it's crucial to diversify the research teams themselves. This means actively involving researchers from varied cultural and geographical backgrounds, particularly those from the Global South where research infrastructure and funding are both often limited. By diversifying research dissemination, we can ensure that a broader range of perspectives is heard and valued.
  4. Expanding Methodological Approaches: Moreover, it's vital to go beyond the traditional quantitative methods considered staples in behavioral science. Embracing qualitative, participatory, and culturally sensitive research designs (like participatory research or ethnographic research, even better if they have locally developed methods!) allows for a deeper and more nuanced understanding of different cultures and societies. This methodological diversity is key to capturing the rich variety of human experiences.
  5. Embracing Diverse Data Sources: While WEIRD samples have been the low-hanging fruit of research, a world of untapped knowledge awaits beyond. This might mean in-depth studies of specific non-WEIRD communities or tapping into alternative data sources like mobile data, social media analytics, and local surveys that can capture the behaviors and attitudes of non-WEIRD populations. These can unlock profound cross-cultural insights, enriching our understanding of the human experience.
  6. Reporting Our Findings: If you are an applied behavioral scientist working in unique contexts beyond WEIRD populations, you hold a powerful treasure trove – the firsthand knowledge of how interventions and research play out in vastly different settings. To combat the WEIRD bias effectively, let's not keep these insights locked away! Sharing our lessons and tools openly can be a game-changer for the field.
  7. Challenging the Status Quo: Finally, it's vital to regularly challenge the prevailing assumptions that stem from a predominantly WEIRD-centric research perspective. Advocating for the inclusion of diverse research samples, methodologies, and researchers are just some of the possible ways we could improve current research practices in the field.

Moving beyond the WEIRD bubble isn't just an academic pursuit; it's transformation with real-world impact. This isn't just about understanding ourselves better; it's about crafting interventions, policies, and solutions that better resonate with our target population. I hope, like the researchers before me, that this is the future of behavioral science – a science where being WEIRD isn’t normal and every study is culturally matched.


  1. Henrich, J., Heine, S. J., & Norenzayan, A. (2010). The weirdest people in the world? SSRN Electronic Journal.
  2. Arnett, J. J. (2008). The neglected 95%: Why American psychology needs to become less American. American Psychologist, 63(7), 602-614.
  3. 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.
  4. 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.
  5. Wendel, S. (2023). We're WEIRD. In Z. Khan & L. Artavia-Mora (Eds.), Behavioral science for development: Insights and strategies for global impact. Bescy.
  6. Syed, M. (2021, June 10). WEIRD times: Three reasons to stop using a silly acronym. Get Syeducated. 
  7. 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 
  8. 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.
  9. 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 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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