Migration Patterns Predict Emotional Expressiveness

Displays of emotion are related to a nation's history of immigrant diversity.

Posted Jul 24, 2019

I once heard a story, perhaps apocryphal, about how the Persian Gulf War could have been avoided if American and Iraqi diplomats had known more about cultural norms regarding the public display of emotions.

In 1990, at the direction of Saddam Hussein, the Iraqi army invaded Kuwait, its neighbor to the south, in an attempt to control Kuwaiti oil fields. President George H. W. Bush quickly formed a coalition of 39 nations to oppose Iraq's land grab.

 U.S. Department of State
Secretary of State James Baker
Source: U.S. Department of State

In January 1991, James Baker, the U.S. Secretary of State, and Tariq Aziz, Iraq's foreign minister, met in Geneva, Switzerland, to discuss a diplomatic solution to the crisis. Seated next to Aziz was Saddam Hussein's half-brother, who periodically called Baghdad to give Hussein his assessment of the negotiations.

James Baker, a reserved man who rarely raised his voice or showed emotion, said very clearly and plainly that the United States and its coalition partners would launch a counteroffensive if Iraq did not pull its troops out of Kuwait.

Unfortunately, the Iraqis paid too little attention to what Baker said and too much attention to how he said it. Hussein’s half-brother reported to Baghdad, "The Americans will not attack. They are weak. They are calm. They are not angry. They are only talking.”

Six days later, President Bush unleashed Operation Desert Storm. Two months later, more than 150,000 Iraqis had lost their lives and the region had sustained $200 billion in property damage.

People who travel internationally quickly learn that different cultures have different rules about when and how to express emotions in public. People in some Asian and Nordic countries, for example, are famously reserved. Arabs and Latin Americans, on the other hand, are often said to be very expressive.

This raises an interesting question: Why do different cultures have different rules regarding emotional expressiveness? According to University of Wisconsin social psychologist Paula Niedenthal, one likely answer is different patterns of "historical heterogeneity."

Historical heterogeneity (HH) refers to the long-term migratory history of a country or region. The United States, Canada, and Australia, for example, have high HH. Over the years, many countries have contributed immigrants to their respective populations. In the United States alone, the list includes England, Ireland, West African countries, Scandinavian countries, Arab countries, Germany, Greece, Italy, Russia, Poland, Mexico, China, Japan, and Vietnam.

In contrast, China and Japan are countries that, historically, have had little in-migration. The same can be said of Estonia, Finland, and Norway. They are low HH countries. As a result, their populations today are ethnically and culturally homogeneous compared to other countries.

According to Niedenthal, people from high HH countries will be more emotionally expressive than people from low HH countries. They will, for example, smile more broadly and more frequently than people who live in countries with no history of in-migration.

Why might this be the case? In an article published last month in the journal Perspectives on Psychological Science, Niedenthal and her colleagues say countries that accept lots of immigrants must adapt to a situation in which basic communication is hindered by the lack of a commonly spoken language. One way to adapt is to encourage people to show their feelings freely and smile in public, thereby making it easier to form social connections with strangers and build social trust.

There is a surprising amount of evidence to support Niedenthal's clever hypothesis.

In a study of more than 5,000 participants in 32 countries, people living in high HH countries were more likely to report display rules that encouraged the direct, overt expression of felt emotion (Rychlowska et al., 2015).

 Lawrence White
Source: Lawrence White

In a study with participants from 79 cultural groups, people living in historically heterogeneous countries expressed emotions on their face in a way that made it easier for others to correctly decode (interpret) their felt emotion (Wood, Rychlowska, & Niedenthal, 2016).

Yet another study used a facial-coding algorithm to analyze the spontaneous smiles of more than 800,000 participants from 31 countries as they watched TV commercials in a market research facility (Girard & McDuff, 2017).

Hester White, used with permission
Source: Hester White, used with permission

The single best predictor of how often people smiled was their country's ancestral diversity. People from countries with the highest ancestral diversity (Panama and the United States) smiled twice as much as people from countries with the lowest ancestral diversity (China and the Philippines).

Finally, a recent study found that people living in U.S. states with high HH, such as California and New York, smiled and laughed more often than people living in states with low HH, such as those in the Deep South (Niedenthal et al., 2018).

In sum, the cultural differences that exist today regarding emotional expressiveness can be explained by long-term migratory patterns. When a society has large numbers of immigrants from many different countries, society adapts by "teaching" people to show their feelings clearly instead of hiding them. People in these societies are encouraged to smile and express positive feelings so as to create rewarding interactions and form social bonds with people who are culturally different.

The studies conducted by Professor Niedenthal and her colleagues are good examples of a new subfield called geographical psychology. Also, the first family pictured is from Estonia, a low HH country. The second family pictured is from the United States, a high HH country.


Niedenthal, P. M., Rychlowska, M., Wood, A., & Zhao, F. (2018). Heterogeneity of long-history migration predicts smiling, laughter and positive emotion across yhe globe and within the United States. PLOS ONE, 13(8), Article e0197651.

Niedenthal, P. M., Rychlowska, M., Zhao, F., & Wood, A. (2019). Historical migration patterns shape contemporary cultures of emotion. Perspectives on Psychological Science, 14(4), 560-573.

Rychlowska, M., and 8 others. (2015). Heterogeneity of long-history migration explains cultural differences in reports of emotional expressivity and the functions of smiles. Proceedings of the National Academy of Sciences, USA, 112, E2429-E2436. doi:10.1073/pnas.1413661112

Wood, A., Rychlowska, M., & Niedenthal, P. M. (2016). Heterogeneity of long-history migration predicts emotion recognition accuracy. Emotion, 16, 413-420.

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