The last Talmudic demon? The role of ritual in cultural transmission.

Recent work on the evolution of religion has approached religions as adaptive complexes of traits consisting of cognitive, neurological, affective, behavioural and developmental features that are organized into a self-regulating feedback system. Religious systems, it has been argued, derive from ancestral ritual systems and continue to be fuelled by ritual performances. One key prediction that emerges from this systemic approach is that the success of religious beliefs will be related to how well they are connected to rituals and integrated with other elements of the religious system. Here, I examine this prediction by exploring the rich world of Jewish demonology. As a case study, I briefly survey the historical trajectory of demonic beliefs across Jewish communities and focus on one demon, a ruach ra'ah, that has survived the vicissitudes of Jewish history and maintained its relevance in contemporary Jewish communities. I argue that it has done so because of its linkage with a morning handwashing ritual and its effective integration into the core elements of Jewish religious systems. This article is part of the theme issue 'Ritual renaissance: new insights into the most human of behaviours'.