Extramarital partnerships are highly stigmatized in many societies and are typically excluded from studies of family dynamics and social support. Nevertheless, in many societies such relationships are common and can have important impacts on resource security and health outcomes. However, current studies of these relationships come mainly from ethnographic studies, with quantitative data extremely rare. Here we present data from a 10-year study of romantic partnerships among a community of Himba pastoralists in Namibia, where concurrency is common. The majority of married men (97%) and women (78%) currently reported having more than one partner (n = 122). Using multilevel models comparing marital and nonmarital relationships, we found that, contrary to conventional wisdom surrounding concurrency, Himba form enduring bonds with extramarital partners that often last decades and are very similar to marital ones in terms of length, emotional affect, reliability, and future prospects. Qualitative interview data showed that extramarital relationships were imbued with a set of rights and obligations that, while distinct from those of spouses, provide an important source of support. Greater inclusion of these relationships in studies of marriage and family would provide a clearer picture of social support and resource transfers in these communities and help to explain variation in the practice and acceptance of concurrency around the world.

婚外伴侣关系在许多社会中受到高度侮辱，并且通常被排除在家庭动态和社会支持的研究之外。然而，在许多社会中，这种关系很常见，并且可能对资源安全和健康结果产生重要影响。然而，目前对这些关系的研究主要来自民族志研究，定量数据极为罕见。在这里，我们提供了一项针对纳米比亚辛巴族牧民社区的浪漫伴侣关系进行的为期 10 年的研究数据，该社区并发性很常见。目前，大多数已婚男性 (97%) 和女性 (78%) 表示拥有多个伴侣（n = 122）。使用比较婚姻和非婚姻关系的多层次模型，我们发现，与关于并发性的传统观点相反，辛巴族与婚外伴侣形成持久的联系，这种联系通常持续数十年，并且在长度、情感影响、可靠性和未来方面与婚姻关系非常相似前景。定性访谈数据显示，婚外关系充满了一系列权利和义务，这些权利和义务虽然与配偶的权利和义务不同，但却提供了重要的支持来源。将这些关系更多地纳入婚姻和家庭研究中，可以更清晰地了解这些社区的社会支持和资源转移，并有助于解释世界各地实践和接受程度的差异。