Over the past 20 years, psychologists have cataloged a long list of differences between East and West (1–3). Western culture is more individualistic and analytic-thinking, whereas East Asian culture is more interdependent 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 intuitive 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 theory (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 individualistic and analytical. World Values Surveys (7) and studies on indigenous Mayans’ transition 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 collectivistic despite per-capita gross domestic products (GDPs) higher than that of the European Union.
The pathogen prevalence theory argues that a high prevalence of communicable diseases 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 openness to experience (6). However, pathogens are strongly correlated with heat (8). Because rice grows in hot areas, pathogens may be confounded with rice—a possibility that prior research did not control for.
The Rice Theory
The rice theory is an extension of subsistence style theory, which argues that some forms of subsistence (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 stability 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 different, and we argue that they lead to different cultures. …
… 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 belong 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 individualistic cultures choose more abstract (analytic) pairings, whereas East Asians and people from other collectivistic cultures choose more relational (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: γ(25) = 0.52, P = 0.03, r = 0.46. (γ 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 holistically: γ(18) = –0.22, P = 0.04, r = –0.44. …
… To test whether the findings generalize beyond thought style, we tested subsamples on two measures previously used for East-West cultural differences. 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 themselves smaller than they drew their friends: γ(24) = –0.20, P = 0.03, r = 0.81 (fig. S2). On average, people from wheat provinces self-inflated 1.5 mm (closer to Europeans), and people from rice provinces self-inflated –0.03 mm (similar to Japanese).
Pathogen prevalence did not predict self-inflation on the sociogram task: γ(17) = 0.003, P = 0.95, r = 0. GDP per capita also failed to predict self-inflation: γ(24) = 0.04, P = 0.81, r = 0.
The second measure was the loyalty and nepotism 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) … People from rice provinces were more likely to show loyalty/nepotism: γ(25) = 2.45, P = 0.04, r = 0.49. In their treatment of strangers, people from rice and wheat provinces did not differ: γ(24) = –0.09, P = 0.90, r = 0. …