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Email: addressed. be should correspondence whom To eateto cnmc,Uiest fHutn oso,T 77004; TX Houston, Houston, of University Economics, of Department society. araca hlrnfo w ifrn omnte n xmndte eaaey u hs tde aenteaie h interaction. the examined not have studies these but separately, them examined and communities different two from children patriarchal euetetr arlna,sneacrigt apel() hr sn remtirhlsceyi h ol,admr eetatrplgclwr eest ou samatrilineal a as Mosuo to refers work anthropological recent more and world, the in society matriarchal true no is there (5), Campbell to according since matrilineal, term the use We u ae tde h oilzto ewe arlna n araca hlrnadhwteitrcinafcsterbhvos hr r aesta aedanmtiieland matrilineal drawn have that papers are There behaviors. their affects interaction the how and children patriarchal and matrilineal between socialization the studies paper Our rmtetoppltos hnte rtetrsho,Msogrstk oerssta ou os hl a il r more response in are malleable girls Mosuo and culture Han environment, by while majority-Han shaped are the boys, preferences in Mosuo risk time than that shows spending risks This environments. students setting majority. after more new school the However, a take to of middle differences. preferences girls in and cultural risk Mosuo differences elementary the reflecting school, adopt from such boys, children enter attitudes Han of first risk than to malleability they individual together averse and come When elicit risk Han, sources we populations. patriarchal experiments, two explore traditionally field the the We and and from men. Mosuo survey matrilineal than Using the school. averse populations, distinct attend risk culturally more two of are children where women that show Studies Significance h ou n a ifri aywy,btms oal,te aedsicl ifrn edrnrs h ou r h only the are Mosuo The norms. gender different distinctly have they notably, most but ways, many in differ Han in and groups Mosuo ethnic The two of children the among behaviors risk-taking the studying by questions these answer to seeks paper This n tde aefudwmnt emr ikaes hnmn[e h adokcatrb ce n rsmn(1)]. Grossman and Eckel by chapter handbook the choices career [see in difference men the than explain partially averse could taking risk risk toward more attitudes in be difference this to that women suggested have found Several have studies any | risk a,b,1,2 | socialization n hrnXeigZuo Xuejing Sharon and | peer raieCmosAtiuinNnomrilNDrvtvsLcne40(CBY-NC-ND) (CC 4.0 License Attribution-NonCommercial-NoDerivatives Commons Creative | culture www.pnas.org/lookup/suppl/doi:10.1073/pnas.1808336116/-/DCSupplemental.y c,2 b ainlBra fEooi eerh(BR,Cmrde A018 and 02138; MA Cambridge, (NBER), Research Economic of Bureau National † ou aiytpclyicue ebr on yteties the by bound members includes typically family Mosuo A ∗ ihnti etn,w xmn o nemnln between intermingling how examine we setting, this Within PNAS | pi ,2019 2, April . y | o.116 vol. | o 14 no. | 6713–6719 c School

ECONOMIC SCIENCES 6 +/− standard errors

5

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3 Mean of Lottery Choices 2

1 Mosuo girls Mosuo boys Han girls Han boys

Fig. 1. The means of the lottery choices for each ethnic–gender group.

the children’s father is often excluded from the household. In Mosuo society, women play an important role in the family decision making, which includes household labor arrangement, crop choices, and spending decisions (8). According to Shih (7) and Walsh (9), women in this society enjoy a social status that is higher than or equal to men. There is very limited evidence on why a matrilineal culture would promote risk-taking behaviors among women. One study has found a positive relationship between agriculture income and reproductive success (i.e., number of surviving children) of Mosuo women (10). Therefore, since Mosuo women are often the head of the household, risk-taking behaviors, which could lead to higher income, could be rewarding. An experimental economic paper by Gong and Yang (11) also rationalizes that Mosuo women (men) have more (less) economic responsibility and have more support from their maternal family; hence, they can take on more risk than other cultures. Conversely, Han Chinese have been influenced by Confucianism for thousands of years. The traditional Han family system is patriarchal and patrilineal. The household head of the family is typically the oldest male, who is responsible for major decisions. Kinship in Han families is passed down through the male descent line: sons and their male offspring continue the family name, and they are expected to support their aging parents (12). Women’s status is traditionally subordinate to men. Although the Cultural Revolution in the 1960s challenged these traditional values, some vestiges of male dominance in Han culture remain (13). For example, the prevalence of sex-selected abortion due to a preference for sons is one piece of evidence that patriarchal and patrilineal influences are ingrained in Han culture (14). For this study, we visited Yongning Township located in Ninglang County, Yunnan Province. Yongning has the largest Mosuo population. In this township, Mosuo and Han children attend the same schools, are taught by the same teachers, and interact daily. We conduct surveys and elicit risk preference of Mosuo and Han elementary and middle school children using incentivized experiments. Sample Selection and Experimental Setup In Yongning Township, we selected the four elementary schools with the greatest numbers of Mosuo students to conduct our exper- iments and surveys. These grades 1–5 schools‡ are usually small, with about 10–30 students and just one class per grade. Despite the fact that these schools have the most Mosuo students of any school in the region, Mosuo are still a minority in most grades. The mean share of Mosuo students at school–grade–year level is 40%.§ We studied all first- to fifth-grade Mosuo and Han children: totals of 185 and 167 elementary students in 2015 and 2016, respectively. We also selected students from the only middle school in the township. Our analysis focused on seventh-grade students for reasons that are explained in SI Appendix. Due to budget constraints, of approximately 240 seventh-grade students, we randomly selected roughly 80 Han and Mosuo students each year to participate in our survey/experiment stratified by gender and ethnicity. The charac- teristics of these elementary and middle school students are described in SI Appendix, Table S1. Mosuo tend to have bigger families than Han, which is likely due to their family structure. Mosuo students also report having higher allowances than Han, but the difference is not statistically significant. One might question whether parents can select the school that their children attend based on their preference for cultural assim- ilation. In this particular setting in China, this type of sorting is nearly impossible, since the school assigned is based on one’s hukou (household registration), which is defined at birth and is passed on by one’s parents’ status (16). Switching hukou in the rural area from one address to another is extremely difficult, since the land/residence is centrally assigned at the village level. We collected survey data and used techniques from experimental economics to elicit risk attitudes. The risk experiment that we conducted is an incentivized lottery choice game from the experimental economic literature. This protocol, which is modeled after the works of Eckel and Grossman (17) and Binswanger (18), has been used by economists when the subjects are less educated. Each student can choose only one of the six lotteries presented, and their choice is not seen by their classmates. Students are instructed

‡In poor rural areas, most students do not attend kindergarten before first grade. For sixth grade, students from these four smaller schools attend another elementary school along with students from other elementary schools. The school with sixth grade is not one of the chosen schools; hence, we only have first to fifth graders and the seventh graders from middle school. §Yi (patriarchal society) is the largest minority group in Ninglang County; however, two of the four elementary schools that we visited have no Yi students. Therefore, unlike other works by Gong and Yang (11) and Zhang (15), which compare risk-taking/competitiveness behaviors of Yi and Mosuo adults/high school students, we decided not to use Yi students as subjects in our paper.

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Table Appendix, SI 1 1 × + γ γ β 1 1 4 ou minority Mosuo γ + + Female 5 γ γ i Mosuo 4 4 i × + schr r ou.Teetr ersinrsl srpre in reported is result regression entire The Mosuo. are cohort ’s ∆ γ 5 i i + × + i γ Mosuo qasoei individual if one equals β 7 2 3 Female r eotdi oun2of 2 column in reported are i + i β × 5 ∆ ∆ i i + .8*[52] −0.183* −0.345 .5*[15] 0.452* .2 [60] 0.127 β 6 0.225 0.237 Girls Female † i [66] saMosuo. a is PNAS i + β | 7 oes the ease To . S8 Table Appendix , SI Mosuo pi ,2019 2, April oease To S7. Table Appendix, SI Age i .8*[41] −0.287* + i .0 [52] −0.006 0.302 1.427 steaeo individual of age the is ε | 0.002 0.001 i Boys . P o.116 vol. ‡ † values [10] [56] γ 1 + γ | 4 IAppendix, SI o 14 no. + γ 5 + | γ 6717 7 [3] i is .

ECONOMIC SCIENCES Table 2. Peer effects in middle school Share of non-Mosuo roommates All three best friends Ethnic–gender group goes up by one SD (15%) are non-Mosuo

Mosuo female, β1 + β2 + β3 + β4 0.011 0.367 † Mosuo male, β3 + β4 0.765* 0.828 Han female, β2 + β4 −0.172 −0.502 Han male, β4 −0.045 −0.170 N 129 49

Regression results are reported in SI Appendix, Table S8. This table presents the effects of ∆ changes from zero to one for each of the given ethnic–gender groups. A positive coefficient indicates that one become less risk averse. *Significant at 1%. †Significant at 5%.

records. Unlike the roommate assignment, one’s choice of friends is not random. Mosuo students with more affinity toward Han culture could have more Han friends; therefore, our estimates could be biased. Nevertheless, it is still interesting to explore whether there is any close friend effect. In Eq. 3, we replace ∆i with a dummy variable indicating whether all three best friends are non- Mosuo, and the results are reported in column 3 of Table 2 and SI Appendix, Table S8. Similar to the results on roommates, we also find that Mosuo males are more likely to be less risk averse if all of their best friends are non-Mosuo. Discussion Our analysis makes several contributions to the literature. Our work speaks to the literature on the origin and the fluidity of gender gaps in risk attitudes. Our findings echo the past literature, which suggests that gender differences in risk preferences could be shaped by the environment or culture (21–23). In consideration of our finding that sharing a room with more Han roommates or having Han classmates for a few years could change the risk-taking behaviors of Mosuo students, our work provides empirical evidence that gendered behaviors are malleable at a formative age. Our work provides some evidence of cultural transmission from parent to child, since both Mosuo and Han first graders have gendered behavior that conforms with that of their parents’ culture. This is in line with past findings in the papers by Fern´andez et al. (24) and Fernandez and Fogli (25), which complement the vast literature on the importance of cultural norms and how it affects decision making, economic outcomes, and gender norms [e.g., the works by Heine and Ruby (26), Henrich et al. (27), and Alesina et al. (28)]. We also provide empirical evidence that socialization causes children’s behavior to diverge from their own cultural norms. This echoes the seminal works by Boyd and Richerson (29) and Cavalli-Sforza and Feldman (30) and the theoretical model proposed by Bisin and Verdier (31). We examine one important mechanism through which socialization affects individual preferences—the peer effect. To the best of our knowledge, there are many studies that examine how socialization affects individual behaviors, and many of these exploited similar identification strategies, such as random roommate assignment or random cohort variation. While most of this literature focuses on outcomes, including academic performance, classroom disruption, violent behaviors, drinking behaviors, and illicit drug use (32–34), none have studied how peers from different ethnic groups and opposite gender norms could affect one’s own gender norms. Lastly, our work also speaks to the literature on cross-culture psychology. When Mosuo and Han children come into contact at school, individuals could experience one or all of the four dimensions of acculturation, such as integration, assimilation, separation, and marginalization (4, 35). It is unclear whether they can become alienated from their own culture. This paper provides a case study where we find evidence that most Mosuo children adopt or mimic Han children’s gender norms. In terms of the challenges and limitation of our study, the main challenge is whether subjects actually understand the game. Suppose that some subjects do not understand the game and have made their choice randomly; then, this is a case of classical measurement error. The difference in risk attitudes between genders would be muted, and it would have biased against finding any statistically significant results. In that case, what we have found could be a lower-bound estimate of the true effects. Alternatively, if subjects who do not understand the game still choose in a way that correlates with our key variables of interest because of some third factors, that could possibly bias our results. We examine this issue in the following ways. First, we test whether there is any systematic pattern that correlates the choices with observables, such as student’s test performance, maternal education, or allowance. We test whether students with above and below observable characteristics have the same lottery choice distribution, and we fail to reject the null hypothesis that they have the same distribution. The details of these results are reported in SI Appendix, Table S9. Second, given that the key variables of interest, such as the interaction term between age, Mosuo, and being in a Mosuo minority cohort (Eq. 2) and the interaction term between Mosuo and the share of Mosuo roommates (Eq 3), are essentially random, it is unlikely that they could be correlated with the unobservable variables. A related concern is that some children may be too young to value the money given in the game. Various studies suggest that, by 6 and 7 y old, children already know the importance of money because of its purchasing power (36). Furthermore, a significant amount of research shows that children’s monetary concepts increase with age without differences between boys and girls (37–39). In our setting, if a given ethnic–gender group has a better understanding of money than others at younger stages, then our results could be biased in Eq. 1. Work by Furth (40) suggests that numbers and numerical concepts are a necessary foundation for enhancing children’s understanding of money; therefore, we regressed math ability (for children in third grade and below) on being Mosuo, female, and Mosuo female, and we do not find any significant correlation between being Mosuo, being female, and math ability (SI Appendix, Table S10). Due to budget and time constraints, we have not examined other important preferences that can also be elicited using experiments, such as competitiveness. We also have not asked about risky behaviors in other domains in the survey. We should also highlight that it is not clear whether the effects that we identify have a sustaining impact or not. It is possible that the change of their behavior is temporary and that they are merely imitating other students or following other role models (e.g., teachers). After the children leave

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Science Conference Kuo Social Experiment American Chiang-Ching Field Conference, of with Consortium Advances support Development school, the Universities Summer acknowledges East Opportunity North Economic Meeting, and Economists Capital Labor pursuing Human of worth Society questions the are Program, Children These norms. culture and ACKNOWLEDGMENTS. gender parents’ their to revert might work. they future villages, in their to return and schools i n Zuo and Liu .Si - 19)Teynnn oo euluin oshl raiain edradehiiyi arlna ulclsceyi otws hn.PDtei (Stanford thesis PhD China. Southwest in society duolocal matrilineal a in n ethnicity From and (2005) ER gender Walsh organization, 9. household (2001) union, H Cai China. Sexual of moso: 8. Na The yongning husbands: The or fathers (1993) without C-k society A Shih (2003) M 7. Stainton H, Cai 6. (2013) A Campbell testosterone. by 5. affected are adaptation. choices and career Acculturation and (1997) DL aversion Sam risk gender. JW, financial on Berry in perspectives differences New 4. evidence. Gender (2011) (2009) Experimental M D Bertrand aversion: Maestripieri L, risk 3. Zingales and S, Paola women Men, 2. (2008) PJ Grossman CC, Eckel 1. nvriy tnod CA). Stanford, University, 291–326. pp 1061–1073. pp 1, Vol Amsterdam), ne ,FgiA lvtiC(04 ohr n os rfrnefrainadfml ao oc dynamics. force labor female and formation Preference sons: and Mothers (2004) C Olivetti A, Fogli R, andez ´ oit ihu ahr rHusbands or Fathers Without Society A oe n h aiyi hns History Chinese in Family the and Women h ol fGonUs hlrnsCnetoso Society of Conceptions Children’s Grown-Ups: of World The ido e w:TeEouinr scooyo Women of Psychology Evolutionary The Own: Her of Mind A oe,teFml,adPaatRvlto nChina in Revolution Peasant and Family, the Women, hns ieg n oit:Fke n Kwangtung and Fukien Society: and Lineage Chinese u on to guo u etakHia agadYnnWn o hi epwt aacleto.W lotaktepriiat fNE dcto and Education NBER of participants the thank also We collection. data with help their for Wang Yunan and Yang Haitao thank We ¨ utr n h vltoayProcess Evolutionary the and Culture u eoitn eiei h ado h mosuo. the of land the in desire negotiating guo u ¨ utrlTasiso n vlto:AQatttv Approach Quantitative A Evolution: and Transmission Cultural ie nedsi e onSci Cogn Rev Interdiscip Wiley d adD sefle NrhHlad a ig) o ,p 1543–1590. pp 4, Vol Diego), San Holland, (North O Ashenfelter D, Card eds Economics, Labor of Handbook Zn ok,Boky,NY). Brooklyn, Books, (Zone adoko rs-utrlPsychology Cross-Cultural of Handbook Rulde London). (Routledge, plPsychol Appl Ui hcg rs,Chicago). Press, Chicago (Univ Ui hcg rs,Chicago). Press, Chicago (Univ Ahoe e ok,Vl33. Vol York), New (Athlone, 46:5–34. Pagr rewo u ru,Wspr,CT). Westport, Group, Pub Greenwood (Praeger, 1:254–266. Ofr nvPes xod ntdKingdom). United Oxford, Press, Univ (Oxford Anthropologica mEo plEcon Appl J Econ Am o China Mod ikUncertainty Risk J mJArcEcon Agric J Am d lt R mt L(ot Holland, (North VL Smith CR, Plott eds Results, Economics Experimental of Handbook mEo Macroeconomics J Econ Am d er W orig H adyJ(ly ao,NehmHihs A,Vl3, Vol MA), Heights, Needham Bacon, & (Allyn J Pandey YH, Poortinga JW, Berry eds , Econ J Q 31:448–486. 45:178. cnTheor Econ J cnmtiaJEooercSoc Econometric J Econometrica PictnUi rs,Princeton). Press, Univ (Princeton 128:469–530. 62:395–407. hn Q China mEo Rev Econ Am 45:265–292. 3:1–33. hl td J Study Child ao Econ Labor J 160:818–855. hlTasRScLn ilSci Biol B Lond Soc R Trans Phil Econ J Q 97:298–319. PNAS 91:73–78. cnBhvOrgan Behav Econ J 1:146–77. 119:1249–1299. 11:33–49. esnlScPsychol Soc Personal J | 27:439–464. Econometrica cnBhvOrgan Behav Econ J pi ,2019 2, April cnBhvOrgan Behav Econ J 59:425–439. rcNt cdSiUSA Sci Acad Natl Proc cnJ Econ 77:1637–1664. cnBhvOrgan Behav Econ J 68:1–17. 129:509–552. | 368:20130081. 34:915–922. o.116 vol. 83:59–65. 99:126–154. 106:15268–15273. | cnJ Econ o 14 no. 111:38–58. 122:208–237. | 6719

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