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Evidence on the nature of sectarian animosity from a geographically representative survey of Iraqi and Iranian Shia pilgrims


Sectarian tensions underlie conflicts across the Middle East, but little is known about their roots and associated beliefs. We conducted a large-scale empirical analysis, drawing on an original, geographically representative survey of over 4,000 devout Shiites across Iran and Iraq. We find that sectarian animosity is linked to economic deprivation, political disillusionment, lack of out-group contact and a sect-based view of domestic politics—paralleling patterns seen in ethno-nationalism elsewhere. In contrast, two alternative accounts are largely unsupported: sectarian animosity is not consistently associated with solidarity with a transnational sect-based community, nor does it seem to stem from disputes over religious doctrine. Nonetheless, this identity’s religious roots manifest in differences from typical ethno-nationalism; practising men are less sectarian, consistent with official doctrine encouraging unity, whereas practising women are more sectarian. These gendered patterns suggest an understudied mechanism: religiously mediated socialization, or the transmission of non-religious norms through religious practice.

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Fig. 1: Testing theorized drivers of sectarian animosity among Iraqi respondents.
Fig. 2: Testing theorized drivers of sectarian animosity among Iranian respondents.
Fig. 3: Worldviews associated with sectarian animosity, by gender.

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The replication data are available via CodeOcean at

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Reproducible code and third-party verified results are available via CodeOcean at


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For support in the field, we thank A. Hammadi, A. A. Y. Al-Kufi (Kufa University president) and H. Nadhem (Kufa University professor). We also thank our survey supervisors F. K. Hasan, M. H. Machi, W. A. Kadhim, F. N. Harram and N. J. Gdhadab and our enumerator team. For advice on surveying in Iraq, we thank A. Jamal and M. Robbins, who generously shared their experience from the Arab Barometer; N. Krishnan, for sharing the instruments and data from the World Bank household economic survey for Iraq; and N. Sahgal, for discussing her experience with the work of the Pew Research Center in Iraq. We thank R. Mottahedeh, S. Mervin and G. Chatelard for early input on the project and M. Alshamary and R. Shaikh for research assistance. F.C. carried out the data collection associated with this project while on an Andrew Carnegie fellowship. She also acknowledges support from ARO MURI (award no. W911NF-121-0509). D.K. acknowledges financial support from the National Science Foundation (Graduate Research Fellowship under grant no. 1122374). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

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F.C. collected the data. E.D. and D.K. analysed the data. F.C., E.D. and D.K. wrote the paper.

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Correspondence to Fotini Christia, Elizabeth Dekeyser or Dean Knox.

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Nature Human Behaviour thanks Justin Gengler, Don van Ravenzwaaij and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Sections 1–6, Tables 1–21 and Figs. 1–7.

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Christia, F., Dekeyser, E. & Knox, D. Evidence on the nature of sectarian animosity from a geographically representative survey of Iraqi and Iranian Shia pilgrims. Nat Hum Behav 6, 1226–1233 (2022).

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