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.

宗派紧张局势是整个中东地区冲突的根源，但人们对其根源和相关信仰知之甚少。我们进行了大规模的实证分析，借鉴了对伊朗和伊拉克 4,000 多名虔诚的什叶派教徒进行的具有地域代表性的原始调查。我们发现，宗派仇恨与经济剥夺、政治幻灭、缺乏与外部群体的接触以及基于宗派的国内政治观点有关——这与其他地方的民族民族主义中的模式相似。相比之下，有两种说法在很大程度上没有得到支持：宗派仇恨并不总是与跨国宗派社区的团结联系在一起，它似乎也不是源于对宗教教义的争论。尽管如此，这种身份的宗教根源与典型的民族民族主义有所不同。从事宗教活动的男性较少宗派，这与鼓励团结的官方教义一致，而从事宗教活动的女性则更具宗派色彩。这些性别模式暗示了一种未被充分研究的机制：以宗教为媒介的社会化，或通过宗教实践传播非宗教规范。