Spontaneous (minimal) ritual in non-human great apes?

Philos Trans R Soc Lond B Biol Sci. 2020 Aug 17;375(1805):20190423. doi: 10.1098/rstb.2019.0423. Epub 2020 Jul 29.


The potential for rituals in non-human great apes (apes) is an understudied topic. We derive a minimal definition of ritual and then examine the currently available evidence for it in untrained and non-enculturated apes. First, we examine whether such apes show evidence for the two main components of our minimal definition of ritual: symbolism and copying. Second, we examine if there are actual cases already identifiable today that may fit all aspects of our minimal definition of ritual-or whether there are at least cases that fit some aspects (proto-ritual). We find that apes are not likely to spontaneously practise minimal ritual, but we claim that the highest expected likelihood of occurrence is in the results-copying domain. Yet, we did not find actual cases of minimal ritual in apes-including those involving environmental results. We did, however, find some cases that may match at least part of our minimal ritual definition-which we termed proto-ritual. At least two out of three potential cases of such proto-rituals that we identified (rain dance, object-in-ear and surplus nest-making procedures) do revolve around results. Overall, apes do not show much, or very clear, evidence for even minimal ritual, but may sometimes show proto-ritual. However, dedicated ape ritual studies are currently lacking, and future work may identify ape ritual (or clearer cases of proto-ritual). We discuss the implications of our preliminary finding for inferences of ritual in the last common ancestor of humans and apes. This article is part of the theme issue 'Ritual renaissance: new insights into the most human of behaviours'.

Keywords: copying; enculturation; non-human great apes; ritual; symbolism.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Ceremonial Behavior*
  • Gorilla gorilla / psychology*
  • Pan paniscus / psychology*
  • Pan troglodytes / psychology*
  • Pongo / psychology*