《社会科学研究方法》课程教学资源（阅读材料）Large-Scale Psychological Differences Within China Explained by Rice Versus Wheat Agriculture

RESEARCH ARTICLES Large-Scale Psychological founded with rice-a possibility that prior re- search did not control for. Differences Within China Explained by The Rice Theory The rice theory is an extension of subsistence style Rice Versus Wheat Agriculture theory,which argues that some forms of subsist- ence(such as farming)require more functional interdependence than other forms(such as herding). T.Talhelm,1*X.Zhang,2.3 S.Oishi,1 C.Shimin,4 D.Duan,2 X.Lan,5 S.Kitayamas At the same time,ecology narrows the types of subsistence that are possible.For example,paddy Cross-cultural psychologists have mostly contrasted East Asia with the West.However, rice requires a significant amount of water.Over this study shows that there are major psychological differences within China.We time,societies that have to cooperate intensely propose that a history of farming rice makes cultures more interdependent,whereas become more interdependent,whereas societies farming wheat makes cultures more independent,and these agricultural legacies that do not have to depend on each other as much continue to affect people in the modern world.We tested 1162 Han Chinese participants become more individualistic. in six sites and found that rice-growing southern China is more interdependent and In the past,most subsistence research has holistic-thinking than the wheat-growing north.To control for confounds like climate, compared herders and farmers,arguing that the we tested people from neighboring counties along the rice-wheat border and found independence and mobility of herding make differences that were just as large.We also find that modernization and pathogen herding cultures individualistic and that the sta- prevalence theories do not fit the data. bility and high labor demands of farming make farming cultures collectivistic(1).We argue that subsistence theory is incomplete because it lumps ver the past 20 years,psychologists have more insular and collectivistic (6).Studies all farming together.Two of the most common cataloged a long list of differences be-have found that historical pathogen prevalence subsistence crops-rice and wheat-are very dif- tween East and West (/-3).Western cul- correlates with collectivism and lower open- ferent,and we argue that they lead to different ture is more individualistic and analytic-thinking, ness to experience (6).However,pathogens are cultures. whereas East Asian culture is more interdepen- strongly correlated with heat(8).Because rice The two biggest differences between farming 5 dent and holistic-thinking.Analytic thought uses grows in hot areas,pathogens may be con- rice and wheat are irrigation and labor.Because abstract categories and formal reasoning,such as 可 logical laws of noncontradiction-if A is true, then'not A"is false.Holistic thought is more intui- tive and sometimes even embraces contradiction- both A and“"notA”can be true. Even though psychology has cataloged a Farmland Deyoted to Rice Paddy long list of East-West differences,it still lacks an accepted explanation of what causes these differences.Building on subsistence style theo- ry (/4),we offer the rice theory of culture and compare it with the modernization hypothesis (5)and the more recent pathogen prevalence theory (6). The modernization hypothesis argues that, as societies become wealthier.more educated. and capitalistic,they become more individu- alistic and analytical.World Values Surveys (7)and studies on indigenous Mayans'transi- tion to a market economy (5)have given some support to the modemization hypothesis.But this theory has difficulty explaining why Japan, Korea,and Hong Kong are persistently col- lectivistic despite per-capita gross domestic Example of rice-wheat products(GDPs)higher than that of the Euro- border at county level pean Union. The pathogen prevalence theory argues that a high prevalence of communicable dis- eases in some countries made it more dangerous 50%Rice to deal with strangers,making those cultures 50%Rice Departmentof Psychology,University of Virginia,Charlottes- Rice-wheat border provinces ville,VA 22904,USA.Department of Psychology,Beijing are highlighted in yellow. Normal University,Beijing,China.State Key Lab of Cognitive Neuroscience and Leaming,Beijing Normal University,Beijing 100875,China."Department of Psychology,South China Normal University,Guangzhou,China.Department of Psy- Fig.1.Percent of cultivated land devoted to rice paddies in 1996.Three major herding provinces chology,University of Michigan,Ann Arbor,MI 48109,USA are not shaded:Tibet,Xinjiang,and Inner Mongolia.Along the rice-wheat border (highlighted),people *Corresponding author.E-mail:tat8dc@virginia.edu from the rice counties thought more holistically than their neighbors in wheat counties. www.sciencemag.org SCIENCE VOL 344 9 MAY 2014 603

Large-Scale Psychological Differences Within China Explained by Rice Versus Wheat Agriculture T. Talhelm,1 * X. Zhang,2,3 S. Oishi,1 C. Shimin,4 D. Duan,2 X. Lan,5 S. Kitayama5 Cross-cultural psychologists have mostly contrasted East Asia with the West. However, this study shows that there are major psychological differences within China. We propose that a history of farming rice makes cultures more interdependent, whereas farming wheat makes cultures more independent, and these agricultural legacies continue to affect people in the modern world. We tested 1162 Han Chinese participants in six sites and found that rice-growing southern China is more interdependent and holistic-thinking than the wheat-growing north. To control for confounds like climate, we tested people from neighboring counties along the rice-wheat border and found differences that were just as large. We also find that modernization and pathogen prevalence theories do not fit the data. Over the past 20 years, psychologists have cataloged a long list of differences be￾tween East and West (1–3). Western cul￾ture is more individualistic and analytic-thinking, whereas East Asian culture is more interdepen￾dent and holistic-thinking. Analytic thought uses abstract categories and formal reasoning, such as logical laws of noncontradiction—if A is true, then “not A” is false. Holistic thought is more intui￾tive and sometimes even embraces contradiction— both A and “not A” can be true. Even though psychology has cataloged a long list of East-West differences, it still lacks an accepted explanation of what causes these differences. Building on subsistence style theo￾ry (1, 4), we offer the rice theory of culture and compare it with the modernization hypothesis (5) and the more recent pathogen prevalence theory (6). The modernization hypothesis argues that, as societies become wealthier, more educated, and capitalistic, they become more individu￾alistic and analytical. World Values Surveys (7) and studies on indigenous Mayans’ transi￾tion to a market economy (5) have given some support to the modernization hypothesis. But this theory has difficulty explaining why Japan, Korea, and Hong Kong are persistently col￾lectivistic despite per-capita gross domestic products (GDPs) higher than that of the Euro￾pean Union. The pathogen prevalence theory argues that a high prevalence of communicable dis￾eases in some countries made it more dangerous to deal with strangers, making those cultures more insular and collectivistic (6). Studies have found that historical pathogen prevalence correlates with collectivism and lower open￾ness to experience (6). However, pathogens are strongly correlated with heat (8). Because rice grows in hot areas, pathogens may be con￾founded with rice—a possibility that prior re￾search did not control for. The Rice Theory The rice theory is an extension of subsistence style theory, which argues that some forms of subsist￾ence (such as farming) require more functional interdependence than other forms (such as herding). At the same time, ecology narrows the types of subsistence that are possible. For example, paddy rice requires a significant amount of water. Over time, societies that have to cooperate intensely become more interdependent, whereas societies that do not have to depend on each other as much become more individualistic. In the past, most subsistence research has compared herders and farmers, arguing that the independence and mobility of herding make herding cultures individualistic and that the sta￾bility and high labor demands of farming make farming cultures collectivistic (1). We argue that subsistence theory is incomplete because it lumps all farming together. Two of the most common subsistence crops—rice and wheat—are very dif￾ferent, and we argue that they lead to different cultures. The two biggest differences between farming rice and wheat are irrigation and labor. Because 1 Department of Psychology, University of Virginia, Charlottes￾ville, VA 22904, USA. 2 Department of Psychology, Beijing Normal University, Beijing, China. 3 State Key Lab of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China. 4 Department of Psychology, South China Normal University, Guangzhou, China. 5 Department of Psy￾chology, University of Michigan, Ann Arbor, MI 48109, USA. *Corresponding author. E-mail: tat8dc@virginia.edu Fig. 1. Percent of cultivated land devoted to rice paddies in 1996. Three major herding provinces are not shaded: Tibet, Xinjiang, and Inner Mongolia. Along the rice-wheat border (highlighted), people from the rice counties thought more holistically than their neighbors in wheat counties. www.sciencemag.org SCIENCE VOL 344 9 MAY 2014 603 RESEARCH ARTICLES on November 24, 2015 www.sciencemag.org Downloaded from

RESEARCH ARTICLES rice paddies need standing water.people in rice in the 1600s advised people,"Ifone is short of labor courages rice farmers to cooperate intensely,form regions build elaborate irrigation systems that re- power,it is best to grow wheat"[quoted in (/0).A tight relationships based on reciprocity,and avoid quire farmers to cooperate.In irigation networks. Chinese anthropologist in the 1930s concluded that behaviors that create conflict. one family's water use can affect their neighbors, a husband and wife would not be able to farm a In comparison,wheat is easier to grow.Wheat so rice farmers have to coordinate their water use. large enough plot of rice to support the family if does not need to be irrigated.so wheat farmers Irigation networks also require many hours each they relied on only their own labor (/)Strict self- can rely on rainfall,which they do not coordinate year to build,dredge,and drain-a burden that reliance might have meant starvation. with their neighbors.Planting and harvesting often falls on villages,not isolated individuals. To deal with the massive labor requirements, wheat certainly takes work.but only halfas much Paddy rice also requires an extraordinary farmers in rice villages from India to Malaysia as rice(9).The lighter burden means farmers can amount of work.Agricultural anthropologists vis- and Japan form cooperative labor exchanges(12). look after their own plots without relying as iting premodem China observed the number of Farmers also coordinate their planting dates so much on their neighbors. hours farmers worked and found that growing that different families harvest at different times, One point of clarification about the rice theo- paddy rice required at least twice the number of allowing them to help in each others'fields(12). ry is that it applies to rice regions,not just the hours as wheat (9).The difference in man-hours These labor exchanges are most common during people farming rice.It is a safe bet that none of was not a difference only noticeable to scientists. transplanting and harvesting,which need to be our thousand participants have actually farmed Medieval Chinese people grew both wheat and done in a short window of time,creating an ur- rice or wheat for a living.Instead,the theory is rice,and they were aware of the huge labor dif- gent need for labor.In economic terms,paddy that cultures that farm rice and wheat over thou- ference between the two.A Chinese farming guide rice makes cooperation more valuable.This en-sands of years pass on rice or wheat cultures. Table 1.Holistic thought hierarchical linear models for rice(28 provinces,1019 participants),GDP per capita(28 provinces,1019 participants),and pathogens(21 provinces,725 participants).See supplementary materials for detailed information on site effects and regressions with GDP,rice,and pathogens in a single model.Gender is coded as 0 male and 1 female. B SE 2 P B SE P B SE P Gender 0.20 0.06 3.55 <0.001 0.20 0.06 3.53 <0.001 0.13 0.07 1.97 0.05 Siterujian -0.34 0.11 -3.21 0.001 -0.33 0.11 -3.07 0.002 -0.36 0.12 -3.09 0.002 Rice 0.56 0.21 2.72 0.007 Per-capita GDP 0.521 0.231 2.241 0.032 Pathogens 0.22 0.102 -2.082 0.042 Predictor correlates in the opposite direction from what theory predicts Table 2.Implicit individualism and loyalty/nepotism hierarchical linear and 452 participants for pathogens.Loyalty/nepotism N equals 27 provinces models for rice,GDP per capita,and pathogens.Implicit individualism N 166 participants for rice and GDP.N equals 21 provinces and 146 participants equals 28 provinces,515 participants for rice and GDP.N equals 21 provinces for pathogens. SE t P SE B SE P Implicit individualism Gender -0.06 0.02 -2.51 0.01 -0.05 0.02 -2.34 0.02 -0.05 0.02 -2.04 0.04 Siteseljingw2011 -0.27 0.05 -5.18 <0.001 -0.25 0.06 -4.40 <0.001 -0.18 0.05 -3.44 0.001 Rice 0.20 0.08 -2.57 0.016 Per-capita GDP 0.01 0.15 0.07 0.95 Pathogens 0.011 0.042 0.331 0.741 Loyalty/Nepotism Sitesichuan 2.04 0.83 2.47 0.01 1.63 0.87 1.88 0.06 1.91 0.85 2.25 0.03 Rice 2.45 1.16 2.12 0.04 Per-capita GDP 1.661 1.691 0.982 0.341 Pathogens -0.13 0.62 -0.21 0.84 Predictor correlates in the opposite direction from what theory predicts Table 3.Divorce and invention regression models for rice,GDP per capita,and pathogens.Divorces are calculated as divorces per marriage,with 27 provinces for rice and per-capita GDP models and 21 provinces for pathogens.Inventions are the log number of successful patents per capita.Inventions N equals 27 provinces for rice and GDP;N equals 21 for pathogens. B SE B t P B SE SE P Divorces Per-capita GDP 0.10 0.040.482.71 0.01 0.13 0.03 0.61 3.89 0.001 0.11 0.05 0.52 2.04 0.06 Rice -0.11 0.04 -0.49 -3.11 0.005 Pathogens -0.01 0.03 -0.07 -0.26 0.80 Inventions Per-capita GDP 2.220.410.735.37 <0.001 2.55 0.370.84 6.98 <0.001 1.78 0.59 0.60 3.00 0.008 Rice -1.27 0.39 -0.39 -3.28 0.003 Pathogens 0.34 0.31 -0.22 -1.10 0.29 604 9 MAY 2014 VOL 344 SCIENCE www.sciencemag.org

rice paddies need standing water, people in rice regions build elaborate irrigation systems that re￾quire farmers to cooperate. In irrigation networks, one family’s water use can affect their neighbors, so rice farmers have to coordinate their water use. Irrigation networks also require many hours each year to build, dredge, and drain—a burden that often falls on villages, not isolated individuals. Paddy rice also requires an extraordinary amount of work. Agricultural anthropologists vis￾iting premodern China observed the number of hours farmers worked and found that growing paddy rice required at least twice the number of hours as wheat (9). The difference in man-hours was not a difference only noticeable to scientists. Medieval Chinese people grew both wheat and rice, and they were aware of the huge labor dif￾ference between the two. A Chinese farming guide in the 1600s advised people, “If one is short of labor power, it is best to grow wheat” [quoted in (10)]. A Chinese anthropologist in the 1930s concluded that a husband and wife would not be able to farm a large enough plot of rice to support the family if they relied on only their own labor (11). Strict self￾reliance might have meant starvation. To deal with the massive labor requirements, farmers in rice villages from India to Malaysia and Japan form cooperative labor exchanges (12). Farmers also coordinate their planting dates so that different families harvest at different times, allowing them to help in each others’ fields (12). These labor exchanges are most common during transplanting and harvesting, which need to be done in a short window of time, creating an ur￾gent need for labor. In economic terms, paddy rice makes cooperation more valuable. This en￾courages rice farmers to cooperate intensely, form tight relationships based on reciprocity, and avoid behaviors that create conflict. In comparison, wheat is easier to grow. Wheat does not need to be irrigated, so wheat farmers can rely on rainfall, which they do not coordinate with their neighbors. Planting and harvesting wheat certainly takes work, but only half as much as rice (9). The lighter burden means farmers can look after their own plots without relying as much on their neighbors. One point of clarification about the rice theo￾ry is that it applies to rice regions, not just the people farming rice. It is a safe bet that none of our thousand participants have actually farmed rice or wheat for a living. Instead, the theory is that cultures that farm rice and wheat over thou￾sands of years pass on rice or wheat cultures, Table 1. Holistic thought hierarchical linear models for rice (28 provinces, 1019 participants), GDP per capita (28 provinces, 1019 participants), and pathogens (21 provinces, 725 participants). See supplementary materials for detailed information on site effects and regressions with GDP, rice, and pathogens in a single model. Gender is coded as 0 = male and 1 = female. B SE zP B SE zPB SE z P Gender 0.20 0.06 3.55 <0.001 0.20 0.06 3.53 <0.001 0.13 0.07 1.97 0.05 SiteFujian –0.34 0.11 –3.21 0.001 –0.33 0.11 –3.07 0.002 –0.36 0.12 –3.09 0.002 Rice 0.56 0.21 2.72 0.007 Per-capita GDP 0.521 0.231 2.241 0.031 Pathogens –0.221 0.101 –2.081 0.041 1 Predictor correlates in the opposite direction from what theory predicts. Table 2. Implicit individualism and loyalty/nepotism hierarchical linear models for rice, GDP per capita, and pathogens. Implicit individualism N equals 28 provinces, 515 participants for rice and GDP. N equals 21 provinces and 452 participants for pathogens. Loyalty/nepotism N equals 27 provinces, 166 participants for rice and GDP. N equals 21 provinces and 146 participants for pathogens. SE tPB SE t PB SE t P Implicit individualism Gender –0.06 0.02 –2.51 0.01 –0.05 0.02 –2.34 0.02 –0.05 0.02 –2.04 0.04 SiteBeijingW2011 –0.27 0.05 –5.18 <0.001 –0.25 0.06 –4.40 <0.001 –0.18 0.05 –3.44 0.001 Rice –0.20 0.08 –2.57 0.016 Per-capita GDP 0.01 0.15 0.07 0.95 Pathogens 0.011 0.041 0.331 0.741 Loyalty/Nepotism SiteSichuan 2.04 0.83 2.47 0.01 1.63 0.87 1.88 0.06 1.91 0.85 2.25 0.03 Rice 2.45 1.16 2.12 0.04 Per-capita GDP 1.661 1.691 0.981 0.341 Pathogens –0.13 0.62 –0.21 0.84 1 Predictor correlates in the opposite direction from what theory predicts. Table 3. Divorce and invention regression models for rice, GDP per capita, and pathogens. Divorces are calculated as divorces per marriage, with 27 provinces for rice and per-capita GDP models and 21 provinces for pathogens. Inventions are the log number of successful patents per capita. Inventions N equals 27 provinces for rice and GDP; N equals 21 for pathogens. B SE b tP B SE b t PB SE b t P Divorces Per-capita GDP 0.10 0.04 0.48 2.71 0.01 0.13 0.03 0.61 3.89 0.001 0.11 0.05 0.52 2.04 0.06 Rice –0.11 0.04 –0.49 –3.11 0.005 Pathogens –0.01 0.03 –0.07 –0.26 0.80 Inventions Per-capita GDP 2.22 0.41 0.73 5.37 <0.001 2.55 0.37 0.84 6.98 <0.001 1.78 0.59 0.60 3.00 0.008 Rice –1.27 0.39 –0.39 –3.28 0.003 Pathogens –0.34 0.31 –0.22 –1.10 0.29 604 9 MAY 2014 VOL 344 SCIENCE www.sciencemag.org RESEARCH ARTICLES

RESEARCH ARTICLES even after most people put down their plows. the past few thousands of years,which controls temperatures(8).Among Chinese provinces,over- Simply put,you do not need to farm rice yourself for some of the major variables that confound all pathogen rates and latitude are correlated: to inherit rice culture East-West comparisons. r(20)=-0.49,P=0.02(l40.Furthermore We propose that the rice theory can partly Within China,the Yangtze River splits the pathogen theory would predict the highest inter- explain East-West differences.Prior subsistence wheat-growing north from the rice-growing dependence in the southwest.which has the high- theory cannot fully explain East-West differences south (Fig.1).For generations,northem China est rates of infectious disease death. because it focuses on herding versus farming (/) has grown wheat,and southem China has grown Third,the rice theory predicts the highest inter- which is not the main East-West difference.Sev- rice.Of course,two regions can never be 100% dependence in the south and east.Unlike path- eral Westem regions herd,such as parts of Scotland equivalent.There are differences such as climate ogens,rice is not the highest in the southernmost and Switzerland,but the bulk of Europe histor- and spoken dialect between north and south.To provinces.Instead,rice is concentrated in the east ically farmed wheat(and similarly grown crops, rule out these smaller differences,we report around Shanghai.which has flat floodplains ideal such as barley).Instead,rice-wheat is the main additional analyses that compare people from for growing rice.The rice theory also predicts a East-West difference,and psychologists have not neighboring counties along the rice-wheat border. sharp divide along the rice-wheat border,which is studied it. different from the gradual rise of pathogens with The easiest way to test whether rice and wheat Three Predictions climate lead to different cultures is to show that rice areas The three theories make different predictions To measure the prevalence of rice farming. (East Asia)are interdependent and that wheat about which parts of China should be the most we used statistical yearbook data on the percent- areas (the West)are independent.But that logic interdependent.First,the modemization hypoth- age of cultivated land in each province devoted to is obviously flawed.We cannot just compare esis predicts that the least-developed provinces rice paddies (/3).Because some rice is grown with East and West because they differ on many fac- should be the most interdependent.Development less labor on dry land (without paddies).we used tors besides rice and wheat-religion,politics, has been uneven in China partly because in the statistics on rice paddies,rather than rice output. and technology,to name a few.A more con- late 1970s Deng Xiaoping made several areas Because we wanted to assess the crop that vincing test case would be a country that has a along the southeast coast "special economic zones" different regions farmed traditionally,rather shared history,goverment,language,and reli- open to foreign trade.This policy has given south- than figures affected by recent advances in irri- gion,but farms rice in some areas and wheat in eastem provinces like Guangdong a GDP per gation and mechanization,we used rice statis- other areas. capita about 3.5 times that of interior provinces tics from 1996,the earliest available on the Bureau like Guizhou (/3).That is roughly the ratio dif- of Statistics Web site. China as a Natural Test Case ference between the United States and Kazakhstan To test the modemization hypothesis,we col- Han China is a fitting natural test case because it Thus.modemization would predict the highest lected GDP per capita for each province from the has traditionally grown both rice and wheat but is collectivism in China's least-developed interior same year.To measure precontemporary dis- more ethnically and politically unified than,say, provinces. ease prevalence,we used the earliest study we Europe or sub-Saharan Africa.China is over Second,pathogen prevalence theory predicts could find with disease rates in different prov- 90%Han Chinese,and the same dynasties have a gradual rise in interdependence from north to inces,from 1976 (/5).Because the 1976 study did ruled over the wheat and rice cores for most of south because pathogens rise gradually along with not cover 10 provinces,we also collected recent statistics (/3).This increased the sample by four provinces.Both sources gave similar pictures: 90 higher disease in the south and the highest in the southwest. Shangha Samples Wetested 1162 Han Chinese students from six sites: Sichuan Rice border enan counties Beijing(north),Fujian(southeast),Guangdong ● (south).Yunnan (southwest).Sichuan (west cen- 80 Guangxl Zhejiang tral),and Liaoning (northeast).We used three Shanx Guangdong o measures:a measure of cultural thought,implicit Hebei Heilongjiang Fujian individualism,and loyalty/nepotism (described be- Liaoning low).We chose these tasks because they are not Hunar self-report scales,avoiding the documented prob- lems with use of self-report scales to measure cul- Shandong Wheat border tural differences (/6). 70 Gansu counties Results from these different sites show that rice-wheat differences held regardless of testing site (14).For all tasks,we analyzed only ethnic Size Divorces per 1,000 marriages Han Chinese and excluded Han participants from the provinces of Tibet,Inner Mongolia,and Xinjiang.These areas are historically herding 60 areas and have different ethnicities,cultures, languages,and religions that would confound Ningxia 60 280 Qinghai our comparisons of rice and wheat. 0 20 40 60% 809 100% We tested the hypotheses with multilevel models because participants (level 1)were nested Percent Cultivated Land Devoted to Rice Paddies within provinces (level 2).We report correlations Fig.2.Cultural thought style by percentage of cultivated area devoted to rice paddies.Each as an effect size at the province level that can be circle represents a province.Circle size represents divorce and controls for effect of GDP.To illustrate compared across variables.We calculated this cultural differences along the rice-wheat border,circles represent the rice and wheat border counties. by comparing the province-level variance of the www.sciencemag.org SCIENCE VOL 344 9 MAY 2014 605

even after most people put down their plows. Simply put, you do not need to farm rice yourself to inherit rice culture. We propose that the rice theory can partly explain East-West differences. Prior subsistence theory cannot fully explain East-West differences because it focuses on herding versus farming (1), which is not the main East-West difference. Sev￾eral Western regions herd, such as parts of Scotland and Switzerland, but the bulk of Europe histor￾ically farmed wheat (and similarly grown crops, such as barley). Instead, rice-wheat is the main East-West difference, and psychologists have not studied it. The easiest way to test whether rice and wheat lead to different cultures is to show that rice areas (East Asia) are interdependent and that wheat areas (the West) are independent. But that logic is obviously flawed. We cannot just compare East and West because they differ on many fac￾tors besides rice and wheat—religion, politics, and technology, to name a few. A more con￾vincing test case would be a country that has a shared history, government, language, and reli￾gion, but farms rice in some areas and wheat in other areas. China as a Natural Test Case Han China is a fitting natural test case because it has traditionally grown both rice and wheat but is more ethnically and politically unified than, say, Europe or sub-Saharan Africa. China is over 90% Han Chinese, and the same dynasties have ruled over the wheat and rice cores for most of the past few thousands of years, which controls for some of the major variables that confound East-West comparisons. Within China, the Yangtze River splits the wheat-growing north from the rice-growing south (Fig. 1). For generations, northern China has grown wheat, and southern China has grown rice. Of course, two regions can never be 100% equivalent. There are differences such as climate and spoken dialect between north and south. To rule out these smaller differences, we report additional analyses that compare people from neighboring counties along the rice-wheat border. Three Predictions The three theories make different predictions about which parts of China should be the most interdependent. First, the modernization hypoth￾esis predicts that the least-developed provinces should be the most interdependent. Development has been uneven in China partly because in the late 1970s Deng Xiaoping made several areas along the southeast coast “special economic zones” open to foreign trade. This policy has given south￾eastern provinces like Guangdong a GDP per capita about 3.5 times that of interior provinces like Guizhou (13). That is roughly the ratio dif￾ference between the United States and Kazakhstan. Thus, modernization would predict the highest collectivism in China’s least-developed interior provinces. Second, pathogen prevalence theory predicts a gradual rise in interdependence from north to south because pathogens rise gradually along with temperatures (8). Among Chinese provinces, over￾all pathogen rates and latitude are correlated: r(20) = –0.49, P = 0.02 (14). Furthermore, pathogen theory would predict the highest inter￾dependence in the southwest, which has the high￾est rates of infectious disease death. Third, the rice theory predicts the highest inter￾dependence in the south and east. Unlike path￾ogens, rice is not the highest in the southernmost provinces. Instead, rice is concentrated in the east around Shanghai, which has flat floodplains ideal for growing rice. The rice theory also predicts a sharp divide along the rice-wheat border, which is different from the gradual rise of pathogens with climate. To measure the prevalence of rice farming, we used statistical yearbook data on the percent￾age of cultivated land in each province devoted to rice paddies (13). Because some rice is grown with less labor on dry land (without paddies), we used statistics on rice paddies, rather than rice output. Because we wanted to assess the crop that different regions farmed traditionally, rather than figures affected by recent advances in irri￾gation and mechanization, we used rice statis￾tics from 1996, the earliest available on the Bureau of Statistics Web site. To test the modernization hypothesis, we col￾lected GDP per capita for each province from the same year. To measure precontemporary dis￾ease prevalence, we used the earliest study we could find with disease rates in different prov￾inces, from 1976 (15). Because the 1976 study did not cover 10 provinces, we also collected recent statistics (13). This increased the sample by four provinces. Both sources gave similar pictures: higher disease in the south and the highest in the southwest. Samples We tested 1162 Han Chinese students from six sites: Beijing (north), Fujian (southeast), Guangdong (south), Yunnan (southwest), Sichuan (west cen￾tral), and Liaoning (northeast). We used three measures: a measure of cultural thought, implicit individualism, and loyalty/nepotism (described be￾low). We chose these tasks because they are not self-report scales, avoiding the documented prob￾lems with use of self-report scales to measure cul￾tural differences (16). Results from these different sites show that rice-wheat differences held regardless of testing site (14). For all tasks, we analyzed only ethnic Han Chinese and excluded Han participants from the provinces of Tibet, Inner Mongolia, and Xinjiang. These areas are historically herding areas and have different ethnicities, cultures, languages, and religions that would confound our comparisons of rice and wheat. We tested the hypotheses with multilevel models because participants (level 1) were nested within provinces (level 2). We report correlations as an effect size at the province level that can be compared across variables. We calculated this by comparing the province-level variance of the Fig. 2. Cultural thought style by percentage of cultivated area devoted to rice paddies. Each circle represents a province. Circle size represents divorce and controls for effect of GDP. To illustrate cultural differences along the rice-wheat border, circles represent the rice and wheat border counties. www.sciencemag.org SCIENCE VOL 344 9 MAY 2014 605 RESEARCH ARTICLES

RESEARCH ARTICLES models with and without the key predictor (Tables 1 Huainan county farms 67%.We tested for dif- selves smaller than they drew their friends:y(24)= to 3 report regression output). ferences in cultural thought style,which had the -0.20,P=0.03,r=-0.17(figS2).0 n average, Our main dependent variable was a common largest sample,including 224 participants from people from wheat provinces self-inflated 1.5 mm measure of cultural thought,the triad task (/7). the rice-wheat border. (closer to Europeans),and people from rice prov- The triad task shows participants lists of three People from the rice side of the border thought inces self-inflated-0.03 mm (similar to Japanese). items,such as train,bus,and tracks.Participants more holistically than people from the wheat Pathogen prevalence did not predict self- decide which two items should be paired together. side of the border:B(221)=0.54.P50%.) distinction between friends and strangers (3).A tional (holistic)pairings(1,1)).We report scores To test whether the findings generalize beyond previous study measured this by having people as a percentage ofholistic choices,where 100% thought style,we tested subsamples on two mea- imagine going into a business deal with (i)an is completely holistic and 0%is completely sures previously used for East-West cultural dif- honest friend,(ii）a dishonest friend,(iii）an analytic. ferences.The first was the sociogram task (n= honest stranger,and(iv)a dishonest stranger We first tested the modemization hypothesis by 515).which has participants draw a diagram of (19).In the stories,the friend or stranger's lies testing whether people from provinces with lower their social network,with circles to represent the cause the participant to lose money in a busi- GDP per capita thought more holistically.People self and friends (18).Researchers measure how ness deal,and the honesty causes the participant from richer provinces actually thought more large participants draw the self versus how large to make more money.In each case,the partici- holistically:y(25)=0.52,P=0.03,r=0.46. they draw their friends to get an implicit measure pants have a chance to use their own money to (y represents province-level HLM regression of individualism (or self-inflation).A prior study reward or punish the other person coefficients.) found that Americans draw themselves about 6 mm The original study found that Singaporeans We then tested the pathogen prevalence theory bigger than they draw others,Europeans draw rewarded their friends much more than they pun- by testing whether provinces with higher rates of themselves 3.5 mm bigger,and Japanese draw ished them,which could be seen positively as disease thought more holistically.Provinces with themselves slightly smaller (/8). loyalty or negatively as nepotism (/9).Americans higher disease rates actually thought less holisti- People from rice provinces were more likely were much more likely than Singaporeans to cally::y(18)=-0.22,P=0.04,r=-0.44. than people from wheat provinces to draw them- punish their friends for bad behavior.We pre- The large-scale disease study from 1976 in- cluded statistics for 31 counties across China Table 4.Instrumental variable regressions.Instrumental variable regressions help test whether (15),which let us test the pathogen theory more reverse causality is a problem in the data set-whether regions that were already more collectivistic chose precisely.Thus,we tested whether the 198 people to grow rice.In the topmost regression,"rice suitability"is a z score of the environmental suitability of in our sample who came from these 31 counties each province for growing wetland rice based on the United Nations Food and Agriculture Organization's had different thought styles based on the histor- Global Agro-ecological Zones database (27).In the five other regressions,rice suitability"is the predicted rice from the topmost regression with rice suitability.Dash entries indicate not applicable. ical disease prevalence in their county.Even with this finer precision,pathogen prevalence pre- B SE B t业 P dicted thought style marginally in the wrong direction:y(28)=-0.43,P=0.08.r=-0.33. Actual rice farming The rice theory was the only model that fit the Rice suitability 0.27 0.03 0.85 8.31 <0.001 data(Fig.2).People from provinces with a higher 28 provinces percentage of farmland devoted to rice paddies Holistic thought thought more holistically:Y(25)=0.56,P=0.007, Gender 0.20 0.06 3.56 <0.001 Siterujian -0.34 0.11 -3.16 0.002 =0.51.[Controlling for GDP per capita made little difference (table S1).] Rice suitability 0.66 0.25 2.66 0.008 Northern and southern China also differ in 28 provinces,1019 participants several factors other than rice,such as climate, Implicit individualism dialect,and contact with herding cultures.There- Gender -0.05 0.02 -2.35 0.02 fore,we analyzed differences among neighboring Sitegeijingw2011 -0.24 0.05 -4.87 <0.001 Rice suitability -0.24 0.10 -2.47 0.02 counties along in the five central provinces along the rice-wheat border(Sichuan,Chongging,Hubei, 28 provinces,510 participants Anhui,and Jiangsu).Differences between neigh- Loyalty/nepotism boring counties are less likely to be due to climate Sitesichuan 1.64 0.80 2.05 0.04 or other third variables. Rice suitability 3.73 1.40 2.67 0.009 We gathered the rice cultivation statistics for 27 provinces,176 participants each county in these provinces and split counties Divorces into rice and wheat counties.We defined rice Per-capita GDP 0.11 0.03 0.51 3.65 0.001 counties as more than 50%of farmland devoted Rice suitability -0.15 0.04 -0.56 -4.04 <0.001 to rice paddies.Figure 1 depicts an example of 27 provinces the county split in the province of Anhui.The Inventions rice-wheat difference between neighboring coun- Per-capita GDP 2.30 0.34 0.76 6.68 <0.001 ties can be stark.For example,in Anhui,Bozhou Rice suitability -1.50 0.43 0.40 -3.50 <0.002 county farms only 2%rice,whereas neighboring 27 provinces 606 9 MAY 2014 VOL 344 SCIENCE www.sciencemag.org

models with and without the key predictor (Tables 1 to 3 report regression output). Our main dependent variable was a common measure of cultural thought, the triad task (17). The triad task shows participants lists of three items, such as train, bus, and tracks. Participants decide which two items should be paired together. Two of the items can be paired because they be￾long to the same abstract category (train and bus belong to the category vehicles), and two because they share a functional relationship (trains run on tracks). People from Western and individu￾alistic cultures choose more abstract (analytic) pairings, whereas East Asians and people from other collectivistic cultures choose more rela￾tional (holistic) pairings (1, 17). We report scores as a percentage of holistic choices, where 100% is completely holistic and 0% is completely analytic. We first tested the modernization hypothesis by testing whether people from provinces with lower GDP per capita thought more holistically. People from richer provinces actually thought more holistically: g(25) = 0.52, P = 0.03, r = 0.46. (g represents province-level HLM regression coefficients.) We then tested the pathogen prevalence theory by testing whether provinces with higher rates of disease thought more holistically. Provinces with higher disease rates actually thought less holisti￾cally: g(18) = –0.22, P = 0.04, r = –0.44. The large-scale disease study from 1976 in￾cluded statistics for 31 counties across China (15), which let us test the pathogen theory more precisely. Thus, we tested whether the 198 people in our sample who came from these 31 counties had different thought styles based on the histor￾ical disease prevalence in their county. Even with this finer precision, pathogen prevalence pre￾dicted thought style marginally in the wrong direction: g(28) = –0.43, P = 0.08, r = –0.33. The rice theory was the only model that fit the data (Fig. 2). People from provinces with a higher percentage of farmland devoted to rice paddies thought more holistically: g(25) = 0.56, P = 0.007, r = 0.51. [Controlling for GDP per capita made little difference (table S1).] Northern and southern China also differ in several factors other than rice, such as climate, dialect, and contact with herding cultures. There￾fore, we analyzed differences among neighboring counties along in the five central provinces along the rice-wheat border (Sichuan, Chongqing, Hubei, Anhui, and Jiangsu). Differences between neigh￾boring counties are less likely to be due to climate or other third variables. We gathered the rice cultivation statistics for each county in these provinces and split counties into rice and wheat counties. We defined rice counties as more than 50% of farmland devoted to rice paddies. Figure 1 depicts an example of the county split in the province of Anhui. The rice-wheat difference between neighboring coun￾ties can be stark. For example, in Anhui, Bozhou county farms only 2% rice, whereas neighboring Huainan county farms 67%. We tested for dif￾ferences in cultural thought style, which had the largest sample, including 224 participants from the rice-wheat border. People from the rice side of the border thought more holistically than people from the wheat side of the border: B(221) = 0.54, P 50%.) To test whether the findings generalize beyond thought style, we tested subsamples on two mea￾sures previously used for East-West cultural dif￾ferences. The first was the sociogram task (n = 515), which has participants draw a diagram of their social network, with circles to represent the self and friends (18). Researchers measure how large participants draw the self versus how large they draw their friends to get an implicit measure of individualism (or self-inflation). A prior study found that Americans draw themselves about 6 mm bigger than they draw others, Europeans draw themselves 3.5 mm bigger, and Japanese draw themselves slightly smaller (18). People from rice provinces were more likely than people from wheat provinces to draw them￾selves smaller than they drew their friends: g(24) = –0.20, P = 0.03, r = –0.17 (fig. S2). On average, people from wheat provinces self-inflated 1.5 mm (closer to Europeans), and people from rice prov￾inces self-inflated –0.03 mm (similar to Japanese). Pathogen prevalence did not predict self￾inflation on the sociogram task: g(17) = 0.003, P = 0.95, r = 0. GDP per capita also failed to predict self-inflation: g(24) = 0.04, P = 0.81, r = 0. The second measure was the loyalty and nep￾otism task, which measures whether people draw a sharp distinction between how they treat friends versus strangers (n = 166). One defining feature of collectivistic cultures is that they draw a sharp distinction between friends and strangers (3). A previous study measured this by having people imagine going into a business deal with (i) an honest friend, (ii) a dishonest friend, (iii) an honest stranger, and (iv) a dishonest stranger (19). In the stories, the friend or stranger’s lies cause the participant to lose money in a busi￾ness deal, and the honesty causes the participant to make more money. In each case, the partici￾pants have a chance to use their own money to reward or punish the other person. The original study found that Singaporeans rewarded their friends much more than they pun￾ished them, which could be seen positively as loyalty or negatively as nepotism (19). Americans were much more likely than Singaporeans to punish their friends for bad behavior. We pre￾Table 4. Instrumental variable regressions. Instrumental variable regressions help test whether reverse causality is a problem in the data set—whether regions that were already more collectivistic chose to grow rice. In the topmost regression, “rice suitability” is a z score of the environmental suitability of each province for growing wetland rice based on the United Nations Food and Agriculture Organization’s Global Agro-ecological Zones database (27). In the five other regressions, “rice suitability” is the predicted rice from the topmost regression with rice suitability. Dash entries indicate not applicable. B SE b t/z P Actual rice farming Rice suitability 0.27 0.03 0.85 8.31 <0.001 28 provinces Holistic thought Gender 0.20 0.06 – 3.56 <0.001 SiteFujian –0.34 0.11 – –3.16 0.002 Rice suitability 0.66 0.25 – 2.66 0.008 28 provinces, 1019 participants Implicit individualism Gender –0.05 0.02 – –2.35 0.02 SiteBeijingW2011 –0.24 0.05 – –4.87 <0.001 Rice suitability –0.24 0.10 – –2.47 0.02 28 provinces, 510 participants Loyalty/nepotism SiteSichuan 1.64 0.80 – 2.05 0.04 Rice suitability 3.73 1.40 – 2.67 0.009 27 provinces, 176 participants Divorces Per-capita GDP 0.11 0.03 0.51 3.65 0.001 Rice suitability –0.15 0.04 –0.56 –4.04 <0.001 27 provinces Inventions Per-capita GDP 2.30 0.34 0.76 6.68 <0.001 Rice suitability –1.50 0.43 –0.40 –3.50 <0.002 27 provinces 606 9 MAY 2014 VOL 344 SCIENCE www.sciencemag.org RESEARCH ARTICLES

RESEARCH ARTICLES dicted that people from rice areas would be less tions than rice provinces.This difference per- which grow rice without irrigation.Studies can likely to punish their friends than people from sisted through the 2000 statistics but not the 2010 also explore how rice differences persist in the wheat areas statistics. modern world.whether through values,institu- We computed loyalty/nepotism as the amount This study shows that China's wheat and rice tions,or other mechanisms. they rewarded their friend minus the amount regions have different cultures.China's rice re- There is also the question of how long rice they punished their friend.People from rice prov- gions have several markers of East Asian culture: culture will persist after the majority of people stop inces were more likely to show loyalty/nepotism: more holistic thought,more interdependent self- farming rice.There is evidence that U.S.regions Y(25)=2.45,P=0.04,r=0.49.In their treatment construals.and lower divorce rates.The wheat- settled by Scottish and Irish herders have higher of strangers,people from rice and wheat provinces growing north looked more culturally similar to rates of violence,even though most locals stopped did not differ:Y(24)=-0.09,P=0.90,r=0. the West,with more analytic thought,indi- herding long ago(24).This is one example of how Pathogen prevalence was not related to vidualism,and divorce.Furthermore.Table 4 subsistence style can shape culture long after loyalty/nepotism:y(19)=-0.13,P=0.84,r= presents an instrumental variable regression people have stopped relying on that subsistence -0.08.GDP per capita did not predict loyalty/ showing that climatic suitability for rice signif- style.In the case of China,only time will tell. nepotism:y(25)=1.66,P=0.36,r=0.33. icantly predicts all of the cultural variables in this Psychologists.economists,and anthropolo- In short,the results consistently showed that study,which suggests that reverse causality is gists have studied the effects of subsistence style participants from rice provinces are more holistic- unlikely. and irrigation (I,4.25,26).This study extends thinking,interdependent,and loyal/nepotistic than How large are these differences compared with that work by using psychological measures to test participants from the wheat provinces.However, East-West differences?We compared results on differences resulting from rice and wheat agri- one weakness of these studies is that the partic- our main task (cultural thought style)in our China culture.The rice theory provides a theoretical frame- ipants were all college students.To test whether sample to a prior U.S.sample.An East-West work that might explain why East Asia is so much the cultural differences extend beyond college categorical variable had an effect of B=0.78.In less individualistic than it"should be"based on students,we gathered provincial statistics on the China data,a categorical rice-wheat variable its wealth.Finally,the rice theory can explain the variables that have been linked to collectivism had an effect of B=0.38 (table S2).This suggests large cultural differences within China,advanc- and analytic thought:divorce rates and patents that rice versus wheat can explain a portion of the ing a more nuanced picture of East Asian cultural for new inventions. variance in thought style between East and West diversity A prior study showed that individualistic coun- but not all of it.It should also be noted that psy- tries have higher divorce rates,even controlling chologists have found holistic thought in parts of References and Notes for gross national product per capita (20).Rice the world beyond East Asia,which suggests holistic 1.R.E.Nisbett,K.Peng.I.Choi,A.Norenzayan,Psychol. culture's emphasis on avoiding conflict and pre- thought is not just an East-West difference (23). ReY108.291-310(2001). 2.H.R.Markus,S.Kitayama,Psychol.Rev.98,224-253 serving relationships may make people from rice Modernization predicted divorce and patents (1991). cultures less willing to get divorced.We collected but why did it fail to predict the other differences? 3.H.C.Triandis,Individualism and Collectivism (Westview, divorce statistics from the same statistical year- In China,modernization seems to have changed Boulder,CO,1995). book as the farming statistics,1996.We also customs such as divorce,but perhaps the parts of 4.]W.Berry,I.Pers.Soc.PsychoL 7.415-418 (1967). collected statistics from the 2000 and the 2010 5.P.M.Greenfield,Dev.Psychol.45,401-418 (2009). culture and thought style we measured are more 6.C.L.Fincher,R.Thornhill,D.R.Murray,M.Schaller, yearbooks to track the differences over the past resistant to change.Or perhaps modernization Pr0c.Biol.Sci.275,1279-1285(2008). 15 years. simply takes more generations to change cultural 7.R.Inglehart,Wash.0.23,215-228(2000) In China,modemization did predict divorce: interdependence and thought style.However. 8.V.Guernier,M.E.Hochberg,].-F.Guegan,PLOS BioL 2 e141(2004. wealthier provinces had more divorce:B(26)= most of our participants were bom after China's 9.).L.Buck,Land Utilization in China (Univ.Chicago Press, 0.10.P=0.01.B=0.48.Adding rice to the model reform and opening,which started in 1978.Fur- Chicago,IL,1935). explained even more variation in divorce rates, thermore,Japan,South Korea,and Hong Kong 10.M.Elvin,in The Chinese Agricultural Economy,R.Barker, with rice provinces having lower divorce rates: moderized much earlier than China,but they still R.Sinha,B.Rose,Eds.(Westview,Boulder,CO,1982), B(25=-0.11.P=0.005,B=-0.49.Pathogen score less individualistic on intemational studies of pp.13-35. 11.F.Xiaotong,Earthbound China:A Study of Rural prevalence did not predict divorce:B(20)=-0.01. culture than their wealth would predict(fig.S2). Economy in Yunnan (Univ.Chicago Press,Chicago,IL, P=0.80,B=-0.07 (controlling for GDP).In 1996. The rice theory can explain wealthy East Asia's 1945). wheat provinces had a 50%higher divorce rate strangely persistent interdependence.China 12.F.Bray,The Rice Economies:Technology and Development than rice provinces.Although divorce rates has a rice-wheat split,but Japan and South Korea in Asian Soceties (Blackwell,New York,1986). 13.State Statistical Bureau of the People's Republic of China, have almost doubled in the past 15 years,the raw are complete rice cultures.Most of China's wheat China Statistical Yearbook (1996 and 2005). divorce rate gap between the wheat and rice provinces devote less than 20%of farmland to 14.Materials and methods are available on Science Online. provinces remained the same in the 2000 and 2010 rice paddies.None of Japan's 9 regions or South 15.C.]unshi,T.C.Campbell,]Li,R.Peto,Diet,Life-Style, statistics. Korea's 16 regions has that little rice (except and Mortality in China:A Study of the Characteristics of 65 Chinese Counties (Oxford Univ.Press,Oxford,1990). We also analyzed the number of successful for two outlying islands).Japan and Korea's 16.K.Peng.R.E.Nisbett,N.Y.C.Wong,Psychol.Methods patents for new inventions in each province be- rice legacies could explain why they are still 2.329-344(1997). cause research has shown that analytic thinkers much less individualistic than similarly wealthy 17.L.]Ji,Z.Zhang.R.E.Nisbett,Pers.Soc.Psychol.87, are better at measures of creativity and thinking countries. 57-65(2004). of novel uses for ordinary objects (21).Within the This study focuses on East Asia.but the rice 18.S.Kitayama,H.Park,A.T.Sevincer,M.Karasawa, A.K.Uskul J.Pers.Soc.Psychol 97,236-255 (2009). United States,immigrants from individualistic theory also makes predictions about other parts 19.C.S.Wang,A.K.-Y.Leung,Y.H.M.See,X.Y.Gao,J.Exp. cultures hold more patents for inventions (22). of the world.For example,India has a large rice- Psychol..47,1295-1299(2011). We controlled for GDP per capita because wheat split.Indonesia and parts of West Africa 20.D.Lester,Psychol.Rep.76,258 (1995). wealthier provinces had more patents:B(26)= have also traditionally farmed rice.If the rice 21.H.A.Witkin,C.A.Moore,D.R.Goodenough,P.W.Cox, Rem.Educ.Rs47,1-64(1977). 2.22,P<0.001,B=0.73.Rice provinces had theory is correct,we should find similar cultural 22.S.A.Shane,J.Bus.Venturing 7,29-46 (1992). fewer successful patents for new inventions than differences there. 23.J.Henrich,S.]Heine,A.Norenzayan,Behov.Broin Sci. wheat provinces:B(25)=-1.27,P=0.003,B= There are still unresolved questions with the 33,61-83,discussion83-135(2010). -0.39.Pathogen prevalence did not predict pat- rice theory.For example,studies can test whether 24.D.Cohen,R.E.Nisbett,Culture of Honor (Westview Boulder,CO,1997). ents:B19)=-034,P=0.29,B=-0.22.Wheat irrigation is central to the effect of rice by com- 25.M.Harris,Cannibals and Kings (Random House, provinces had 30%more patents for inven- paring paddy rice with dryland rice cultures New York,1977). www.sciencemag.org SCIENCE VOL 344 9 MAY 2014 607

dicted that people from rice areas would be less likely to punish their friends than people from wheat areas. We computed loyalty/nepotism as the amount they rewarded their friend minus the amount they punished their friend. People from rice prov￾inces were more likely to show loyalty/nepotism: g(25) = 2.45, P= 0.04,r = 0.49. In their treatment of strangers, people from rice and wheat provinces did not differ: g(24) = –0.09, P = 0.90, r = 0. Pathogen prevalence was not related to loyalty/nepotism: g(19) = –0.13, P = 0.84, r = –0.08. GDP per capita did not predict loyalty/ nepotism: g(25) = 1.66, P = 0.36, r = 0.33. In short, the results consistently showed that participants from rice provinces are more holistic￾thinking, interdependent, and loyal/nepotistic than participants from the wheat provinces. However, one weakness of these studies is that the partic￾ipants were all college students. To test whether the cultural differences extend beyond college students, we gathered provincial statistics on variables that have been linked to collectivism and analytic thought: divorce rates and patents for new inventions. A prior study showed that individualistic coun￾tries have higher divorce rates, even controlling for gross national product per capita (20). Rice culture’s emphasis on avoiding conflict and pre￾serving relationships may make people from rice cultures less willing to get divorced. We collected divorce statistics from the same statistical year￾book as the farming statistics, 1996. We also collected statistics from the 2000 and the 2010 yearbooks to track the differences over the past 15 years. In China, modernization did predict divorce: wealthier provinces had more divorce: B(26) = 0.10, P= 0.01, b = 0.48. Adding rice to the model explained even more variation in divorce rates, with rice provinces having lower divorce rates: B(25) = –0.11, P = 0.005, b = –0.49. Pathogen prevalence did not predict divorce: B(20) = –0.01, P= 0.80, b = –0.07 (controlling for GDP). In 1996, wheat provinces had a 50% higher divorce rate than rice provinces. Although divorce rates have almost doubled in the past 15 years, the raw divorce rate gap between the wheat and rice provinces remained the same in the 2000 and 2010 statistics. We also analyzed the number of successful patents for new inventions in each province be￾cause research has shown that analytic thinkers are better at measures of creativity and thinking of novel uses for ordinary objects (21). Within the United States, immigrants from individualistic cultures hold more patents for inventions (22). We controlled for GDP per capita because wealthier provinces had more patents: B(26) = 2.22, P < 0.001, b = 0.73. Rice provinces had fewer successful patents for new inventions than wheat provinces: B(25) = –1.27, P = 0.003, b = –0.39. Pathogen prevalence did not predict pat￾ents: B(19) = –0.34, P = 0.29, b = –0.22. Wheat provinces had 30% more patents for inven￾tions than rice provinces. This difference per￾sisted through the 2000 statistics but not the 2010 statistics. This study shows that China’s wheat and rice regions have different cultures. China’s rice re￾gions have several markers of East Asian culture: more holistic thought, more interdependent self￾construals, and lower divorce rates. The wheat￾growing north looked more culturally similar to the West, with more analytic thought, indi￾vidualism, and divorce. Furthermore, Table 4 presents an instrumental variable regression showing that climatic suitability for rice signif￾icantly predicts all of the cultural variables in this study, which suggests that reverse causality is unlikely. How large are these differences compared with East-West differences? We compared results on our main task (cultural thought style) in our China sample to a prior U.S. sample. An East-West categorical variable had an effect of B = 0.78. In the China data, a categorical rice-wheat variable had an effect of B = 0.38 (table S2). This suggests that rice versus wheat can explain a portion of the variance in thought style between East and West but not all of it. It should also be noted that psy￾chologists have found holistic thought in parts of the world beyond East Asia, which suggests holistic thought is not just an East-West difference (23). Modernization predicted divorce and patents, but why did it fail to predict the other differences? In China, modernization seems to have changed customs such as divorce, but perhaps the parts of culture and thought style we measured are more resistant to change. Or perhaps modernization simply takes more generations to change cultural interdependence and thought style. However, most of our participants were born after China’s reform and opening, which started in 1978. Fur￾thermore, Japan, South Korea, and Hong Kong modernized much earlier than China, but they still score less individualistic on international studies of culture than their wealth would predict (fig. S2). The rice theory can explain wealthy East Asia’s strangely persistent interdependence. China has a rice-wheat split, but Japan and South Korea are complete rice cultures. Most of China’s wheat provinces devote less than 20% of farmland to rice paddies. None of Japan’s 9 regions or South Korea’s 16 regions has that little rice (except for two outlying islands). Japan and Korea’s rice legacies could explain why they are still much less individualistic than similarly wealthy countries. This study focuses on East Asia, but the rice theory also makes predictions about other parts of the world. For example, India has a large rice￾wheat split. Indonesia and parts of West Africa have also traditionally farmed rice. If the rice theory is correct, we should find similar cultural differences there. There are still unresolved questions with the rice theory. For example, studies can test whether irrigation is central to the effect of rice by com￾paring paddy rice with dryland rice cultures, which grow rice without irrigation. Studies can also explore how rice differences persist in the modern world, whether through values, institu￾tions, or other mechanisms. There is also the question of how long rice culture will persist after the majority of people stop farming rice. There is evidence that U.S. regions settled by Scottish and Irish herders have higher rates of violence, even though most locals stopped herding long ago (24). This is one example of how subsistence style can shape culture long after people have stopped relying on that subsistence style. In the case of China, only time will tell. Psychologists, economists, and anthropolo￾gists have studied the effects of subsistence style and irrigation (1, 4, 25, 26). This study extends that work by using psychological measures to test differences resulting from rice and wheat agri￾culture. The rice theory provides a theoretical frame￾work that might explain why East Asia is so much less individualistic than it “should be” based on its wealth. Finally, the rice theory can explain the large cultural differences within China, advanc￾ing a more nuanced picture of East Asian cultural diversity. References and Notes 1. R. E. Nisbett, K. Peng, I. Choi, A. Norenzayan, Psychol. Rev. 108, 291–310 (2001). 2. H. R. Markus, S. Kitayama, Psychol. Rev. 98, 224–253 (1991). 3. H. C. Triandis, Individualism and Collectivism (Westview, Boulder, CO, 1995). 4. J. W. Berry, J. Pers. Soc. Psychol. 7, 415–418 (1967). 5. P. M. Greenfield, Dev. Psychol. 45, 401–418 (2009). 6. C. L. Fincher, R. Thornhill, D. R. Murray, M. Schaller, Proc. Biol. Sci. 275, 1279–1285 (2008). 7. R. Inglehart, Wash. Q. 23, 215–228 (2000). 8. V. Guernier, M. E. Hochberg, J.-F. Guégan, PLOS Biol. 2, e141 (2004). 9. J. L. Buck, Land Utilization in China (Univ. Chicago Press, Chicago, IL, 1935). 10. M. Elvin, in The Chinese Agricultural Economy, R. Barker, R. Sinha, B. Rose, Eds. (Westview, Boulder, CO, 1982), pp. 13–35. 11. F. Xiaotong, Earthbound China: A Study of Rural Economy in Yunnan (Univ. Chicago Press, Chicago, IL, 1945). 12. F. Bray, The Rice Economies: Technology and Development in Asian Societies (Blackwell, New York, 1986). 13. State Statistical Bureau of the People’s Republic of China, China Statistical Yearbook (1996 and 2005). 14. Materials and methods are available on Science Online. 15. C. Junshi, T. C. Campbell, J. Li, R. Peto, Diet, Life-Style, and Mortality in China: A Study of the Characteristics of 65 Chinese Counties (Oxford Univ. Press, Oxford, 1990). 16. K. Peng, R. E. Nisbett, N. Y. C. Wong, Psychol. Methods 2, 329–344 (1997). 17. L. J. Ji, Z. Zhang, R. E. Nisbett, J. Pers. Soc. Psychol. 87, 57–65 (2004). 18. S. Kitayama, H. Park, A. T. Sevincer, M. Karasawa, A. K. Uskul, J. Pers. Soc. Psychol. 97, 236–255 (2009). 19. C. S. Wang, A. K.-Y. Leung, Y. H. M. See, X. Y. Gao, J. Exp. Psychol. 47, 1295–1299 (2011). 20. D. Lester, Psychol. Rep. 76, 258 (1995). 21. H. A. Witkin, C. A. Moore, D. R. Goodenough, P. W. Cox, Rev. Educ. Res. 47, 1–64 (1977). 22. S. A. Shane, J. Bus. Venturing 7, 29–46 (1992). 23. J. Henrich, S. J. Heine, A. Norenzayan, Behav. Brain Sci. 33, 61–83, discussion 83–135 (2010). 24. D. Cohen, R. E. Nisbett, Culture of Honor (Westview, Boulder, CO, 1997). 25. M. Harris, Cannibals and Kings (Random House, New York, 1977). www.sciencemag.org SCIENCE VOL 344 9 MAY 2014 607 RESEARCH ARTICLES

26.M.Aoki,Toward a Comparative Institutional Analysis (MIT Chinese version of the triad task:M.Hunter for statistical Supplementary Materials Press,Cambridge,MA,2001). quidance;and 1.P.Seder,A Putnam,Y.Wang.T.Wilson,and www.sciencemag.org/content/344/6184/603/suppl/DC1 27.Food and Agricultural Organization (FAOMInternational E.Gilbert for comments on earlier versions of this paper.The data Materials and Methods Institute for Applied Systems Analysis (IIASA),Global are available at the Inter-University Consortium for Political and Figs.S1 and S2 Agro-ecological Zones (GAEZ v3.0)(2010). Social Research (ICPSR no.35027)or by request to the first Tables S1 to $12 author.This research was supported by a Fulbright Scholarship,a References (28-49) Acknowledgments:We thank Z.Xia,N.Qingyun,Y.Wu,Y.Wang, NSF Graduate Research Fellowship,and a NSF East Asian and Y.Ma,and A Jiao for collecting data;A.Leung and C.Wang for Pacific Summer Institute Fellowship.The Beijing Key Lab of Applied 4 October 2013:accepted 25 March 2014 making the loyalty/nepotism task available;L Jun Ji for the Experimental Psychology supplied laboratory space for the study. 10.1126/science.1246850 REPORTS vealed by QO or possibly created by their neces- Fermi Surface and Pseudogap sarily high magnetic fields. A zero-field altemative to QO,angle-resolved Evolution in a Cuprate Superconductor photoemission spectroscopy(ARPES),has a long history of mapping the FS in BiSr2CaCu2Os (Bi2212)(2,7-//).Here,the onset of the pseu- Yang He,1 Yi Yin,1*M.Zech,1 Anjan Soumyanarayanan,1 Michael M.Yee,1 Tess Williams,1 dogap (PG)is defined by the opening of an M.C.Boyer,Kamalesh Chatterjee,2 W.D.Wise,2 I.Zeljkovic,Takeshi Kondo,3s T.Takeuchi,3 H.lkuta,3 Peter Mistark,4 Robert S.Markiewicz,4 Arun Bansil,4 Subir Sachdev,1 antinodal gap and the reduction of the large FS to a"Fermi arc,"which may actually be one side of E.W.Hudson,2I].E.Hoffman2 a Fermi pocket,consistent with QO results (10). The PG onset may be associated with a QPT just The undlear relationship between cuprate superconductivity and the pseudogap state remains an above optimal doping at p=0.19(/D).A second impediment to understanding the high transition temperature (7)superconducting mechanism.Here, QPT to another competing phase is suggested to we used magnetic field-dependent scanning tunneling microscopy to provide phase-sensitive proof occur()at lower doping (p=0.076),similar that d-wave superconductivity coexists with the pseudogap on the antinodal Fermi surface of an perhaps to that found by QO(5,6).However,if overdoped cuprate.Furthermore,by tracking the hole-doping (p)dependence of the quasi-partice the transition near optimal doping is a FS recon- interference pattern within a single bismuth-based cuprate family,we observed a Fermi surface struction to pockets,as suggested in (10),why are reconstruction slightly below optimal doping,indicating a zero-field quantum phase transition in sharp antinodal quasiparticles seen below this notable proximity to the maximum superconducting T.Surprisingly,this major reorganization of the doping,all the way down to p=0.08(7,9.//) system's underlying electronic structure has no effect on the smoothly evolving pseudogap. Further,if the antinodal FS persists down to p 0.08.what impact does the OPT associated with uperconductivity is one of several phenome- insulator transition (5)or the formation of density- the onset of the PG at p=0.19 have on the FS? na,including the pseudogap,that arises wave order(6).However,the large-to-small FS To address these outstanding questions,we from interactions of electrons near the transition presumed to occur at higher doping used scanning tunneling microscopy (STM) Fermi surface(FS)in hole-doped cuprates.The has thus far not been observed by QO within a to study (Bi,Pb)2(Sr,La)2CuO6+8 (Bi2201).In FS topology is therefore crucial to understanding single hole-doped material system.Furthermore, this hole-doped cuprate,the absence of bilayer these phenomena and their relationships.High- it is unclear whether the small FS is merely re- splitting and the suppression of the supermodu- field quantum oscillation (QO)measurements (1-3)revealed an unexpectedly small FS in un- derdoped YBa2Cu3O6.s(YBCO),in contrast to B the conventional,large FS of overdoped cuprates 250 SC.PG ① 3.0 OD15K like Tl2Ba2CuO(4).Further high-field inves- tigations led to the discovery of a quantum phase 200 2.5 OPT35K transition (OPT)at the low doping edge of this small FS regime,perhaps associated with a metal- 150- 2.0 UD32K- PG 1.5 100 Department of Physics,Harvard University,Cambridge,MA 1.0 02138,USA.Department of Physics,Massachusetts Institute AFM Hall anomaly of Technology (MIT),Cambridge,MA02139,USA.Department 50 UD25K- of Crystalline Materials Science,Nagoya University,Nagoya 0.5 464-8603,Japan.Department of Physics,Northeastern Uni versity,Boston,MA 02115,USA. 0.10 0.15 0.20 -10050 0 50100 *Present address:Department of Physics,Zhejiang University. 0.05 Hangzhou,China Estimated p Sample Bias(mV) tPresent address:Department of Physics,Clark University, Fig.1.Phase diagram and spectra.(A)Schematic temperature-doping phase diagram of Bi2201, Worcester,MA 01610,USA. Present address:Department of Physics,Boston College, showing antiferromagnetic insulator (AFM),superconductor (SC),and PG phases.Four black points Chestnut Hill.MA 02467,USA. represent the sample batches of this study,namely underdoped UD25K and UD32K,optimal OPT35K,and SPresent address:Institute for Solid State Physics,Univer- overdoped OD15K.The PG transition line T*is plotted as measured by ARPES (12),resistivity (12)and sity of Tokyo,Tokyo,Japan. nuclear magnetic resonance (13).Anomaly in the Hall coefficient(28)is marked by a black arrow.(B) Present address:Department of Physics,Pennsylvania The spatially averaged differential conductance g(E)for each sample.The PG edge is marked with State University,University Park,PA 16802,USA. Corresponding author.E-mail:jhoffman@physics.harvard. black arrows,whereas the low-energy kink in each spectrum,considered to be related to the super- edu (J.E.H.);ehudson@psu.edu (E.W.H.) conducting gap (14,15),is marked with red arrows.a.u.,arbitrary units. 608 9 MAY 2014 VOL 344 SCIENCE www.sciencemag.org

26. M. Aoki, Toward a Comparative Institutional Analysis (MIT Press, Cambridge, MA, 2001). 27. Food and Agricultural Organization (FAO)/International Institute for Applied Systems Analysis (IIASA), Global Agro-ecological Zones (GAEZ v3.0) (2010). Acknowledgments: We thank Z. Xia, N. Qingyun, Y. Wu, Y. Wang, Y. Ma, and A Jiao for collecting data; A. Leung and C. Wang for making the loyalty/nepotism task available; L. Jun Ji for the Chinese version of the triad task; M. Hunter for statistical guidance; and J. P. Seder, A. Putnam, Y. Wang, T. Wilson, and E. Gilbert for comments on earlier versions of this paper. The data are available at the Inter-University Consortium for Political and Social Research (ICPSR no. 35027) or by request to the first author. This research was supported by a Fulbright Scholarship, a NSF Graduate Research Fellowship, and a NSF East Asian and Pacific Summer Institute Fellowship. The Beijing Key Lab of Applied Experimental Psychology supplied laboratory space for the study. Supplementary Materials www.sciencemag.org/content/344/6184/603/suppl/DC1 Materials and Methods Figs. S1 and S2 Tables S1 to S12 References (28–49) 4 October 2013; accepted 25 March 2014 10.1126/science.1246850 REPORTS Fermi Surface and Pseudogap Evolution in a Cuprate Superconductor Yang He,1 Yi Yin,1 * M. Zech,1 Anjan Soumyanarayanan,1 Michael M. Yee,1 Tess Williams,1 M. C. Boyer,2 † Kamalesh Chatterjee,2 W. D. Wise,2 I. Zeljkovic,1 ‡ Takeshi Kondo,3 § T. Takeuchi,3 H. Ikuta,3 Peter Mistark,4 Robert S. Markiewicz,4 Arun Bansil,4 Subir Sachdev,1 E. W. Hudson,2 ‖¶ J. E. Hoffman1 ¶ The unclear relationship between cuprate superconductivity and the pseudogap state remains an impediment to understanding the high transition temperature (Tc) superconducting mechanism. Here, we used magnetic field–dependent scanning tunneling microscopy to provide phase-sensitive proof that d-wave superconductivity coexists with the pseudogap on the antinodal Fermi surface of an overdoped cuprate. Furthermore, by tracking the hole-doping (p) dependence of the quasi-particle interference pattern within a single bismuth-based cuprate family, we observed a Fermi surface reconstruction slightly below optimal doping, indicating a zero-field quantum phase transition in notable proximity to the maximum superconducting Tc. Surprisingly, this major reorganization of the system’s underlying electronic structure has no effect on the smoothly evolving pseudogap. Superconductivity is one of several phenome￾na, including the pseudogap, that arises from interactions of electrons near the Fermi surface (FS) in hole-doped cuprates. The FS topology is therefore crucial to understanding these phenomena and their relationships. High￾field quantum oscillation (QO) measurements (1–3) revealed an unexpectedly small FS in un￾derdoped YBa2Cu3O6.5 (YBCO), in contrast to the conventional, large FS of overdoped cuprates like Tl2Ba2CuO6+x (4). Further high-field inves￾tigations led to the discovery of a quantum phase transition (QPT) at the low doping edge of this small FS regime, perhaps associated with a metal￾insulator transition (5) or the formation of density￾wave order (6). However, the large-to-small FS transition presumed to occur at higher doping has thus far not been observed by QO within a single hole-doped material system. Furthermore, it is unclear whether the small FS is merely re￾vealed by QO or possibly created by their neces￾sarily high magnetic fields. A zero-field alternative to QO, angle-resolved photoemission spectroscopy (ARPES), has a long history of mapping the FS in Bi2Sr2CaCu2O8+x (Bi2212) (2, 7–11). Here, the onset of the pseu￾dogap (PG) is defined by the opening of an antinodal gap and the reduction of the large FS to a “Fermi arc,” which may actually be one side of a Fermi pocket, consistent with QO results (10). The PG onset may be associated with a QPT just above optimal doping at p = 0.19 (11). A second QPT to another competing phase is suggested to occur (11) at lower doping ( p = 0.076), similar perhaps to that found by QO (5, 6). However, if the transition near optimal doping is a FS recon￾struction to pockets, as suggested in (10), why are sharp antinodal quasiparticles seen below this doping, all the way down to p = 0.08 (7, 9, 11)? Further, if the antinodal FS persists down to p = 0.08, what impact does the QPT associated with the onset of the PG at p = 0.19 have on the FS? To address these outstanding questions, we used scanning tunneling microscopy (STM) to study (Bi,Pb)2(Sr,La)2CuO6+d (Bi2201). In this hole-doped cuprate, the absence of bilayer splitting and the suppression of the supermodu- 1 Department of Physics, Harvard University, Cambridge, MA 02138, USA. 2 Department of Physics, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA. 3 Department of Crystalline Materials Science, Nagoya University, Nagoya 464-8603, Japan. 4 Department of Physics, Northeastern Uni￾versity, Boston, MA 02115, USA. *Present address: Department of Physics, Zhejiang University, Hangzhou, China. †Present address: Department of Physics, Clark University, Worcester, MA 01610, USA. ‡Present address: Department of Physics, Boston College, Chestnut Hill, MA 02467, USA. §Present address: Institute for Solid State Physics, Univer￾sity of Tokyo, Tokyo, Japan. ‖Present address: Department of Physics, Pennsylvania State University, University Park, PA 16802, USA. ¶Corresponding author. E-mail: jhoffman@physics.harvard. edu (J.E.H.); ehudson@psu.edu (E.W.H.) Fig. 1. Phase diagram and spectra. (A) Schematic temperature-doping phase diagram of Bi2201, showing antiferromagnetic insulator (AFM), superconductor (SC), and PG phases. Four black points represent the sample batches of this study, namely underdoped UD25K and UD32K, optimal OPT35K, and overdoped OD15K. The PG transition line T* is plotted as measured by ARPES (12), resistivity (12) and nuclear magnetic resonance (13). Anomaly in the Hall coefficient (28) is marked by a black arrow. (B) The spatially averaged differential conductance g(E) for each sample. The PG edge is marked with black arrows, whereas the low-energy kink in each spectrum, considered to be related to the super￾conducting gap (14, 15), is marked with red arrows. a.u., arbitrary units. 608 9 MAY 2014 VOL 344 SCIENCE www.sciencemag.org

EXTENDED PDF FORMAT SPONSORED BY Sample-Size Antibodies Loam Woro www.rndsystems.com Science Large-Scale Psychological Differences Within China Explained by Rice Versus Wheat Agriculture T.Talhelm et al. Science344,603(2014): AAAAS DO:10.1126/science.1246850 This copy is for your personal,non-commercial use only. If you wish to distribute this article to others,you can order high-quality copies for your colleagues,clients,or customers by clicking here. Permission to republish or repurpose articles or portions of articles can be obtained by following the guidelines here. 惑 The following resources related to this article are available online at www.sciencemag.org(this information is current as of November 24,2015): Updated information and services,including high-resolution figures,can be found in the online version of this article at: http://www.sciencemag.org/content/344/6184/603.full.html Supporting Online Material can be found at: http://www.sciencemag.org/content/suppl/2014/05/07/344.6184.603.DC1.html A list of selected additional articles on the Science Web sites related to this article can be found at: http://www.sciencemag.org/content/344/6184/603.full.html#related This article cites 27 articles,9 of which can be accessed free: http://www.sciencemag.org/content/344/6184/603.full.html#ref-list-1 This article has been cited by 14 articles hosted by HighWire Press;see: http://www.sciencemag.org/content/344/6184/603.full.html#related-urls This article appears in the following subject collections: Psychology http://www.sciencemag.org/cgi/collection/psychology Science(print ISSN 0036-8075;online ISSN 1095-9203)is published weekly,except the last week in December,by the American Association for the Advancement of Science,1200 New York Avenue NW,Washington,DC 20005.Copyright 2014 by the American Association for the Advancement of Science;all rights reserved.The title Science is a registered trademark of AAAS

DOI: 10.1126/science.1246850 Science 344, 603 (2014); T. Talhelm et al. Rice Versus Wheat Agriculture Large-Scale Psychological Differences Within China Explained by This copy is for your personal, non-commercial use only. colleagues, clients, or customers by clicking here. If you wish to distribute this article to others, you can order high-quality copies for your following the guidelines here. Permission to republish or repurpose articles or portions of articles can be obtained by www.sciencemag.org (this information is current as of November 24, 2015 ): The following resources related to this article are available online at http://www.sciencemag.org/content/344/6184/603.full.html version of this article at: Updated information and services, including high-resolution figures, can be found in the online http://www.sciencemag.org/content/suppl/2014/05/07/344.6184.603.DC1.html Supporting Online Material can be found at: http://www.sciencemag.org/content/344/6184/603.full.html#related found at: A list of selected additional articles on the Science Web sites related to this article can be http://www.sciencemag.org/content/344/6184/603.full.html#ref-list-1 This article cites 27 articles, 9 of which can be accessed free: http://www.sciencemag.org/content/344/6184/603.full.html#related-urls This article has been cited by 14 articles hosted by HighWire Press; see: http://www.sciencemag.org/cgi/collection/psychology Psychology This article appears in the following subject collections: registered trademark of AAAS. 2014 by the American Association for the Advancement of Science; all rights reserved. The title Science is a American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. Copyright Science (print ISSN 0036-8075; online ISSN 1095-9203) is published weekly, except the last week in December, by the on November 24, 2015 www.sciencemag.org Downloaded from