At first glance, you may notice that ‘children’s toy’ seems to be the most common use of bullroarers across these societies, however this appears to be concentrated across North American foragers, who are highly overrepresented in the eHRAF World Cultures files, making up 33 of the 54 total hunter-gatherer societies in the database.

While less common than the bullroarer’s use as a children’s toy, we can see that ‘weather manipulation’ may potentially have an even broader geographic distribution, due to the presence of this practice among the Ainu of East Asia (see Table 1). In this case, we cannot necessarily rule out the possibility that this reflects a shared historical origin or diffusion across Beringia, however. See Hallowell’s (1926) investigation of bear ceremonialism across the Northern Hemisphere for a related example.

Where we have clearer evidence of independent invention of bullroarers is through their association with powerful spirits, or other entities, in forager societies that have been highly isolated from each other historically, such as the Arunta of Central Australia, the Mbuti of Central Africa, the Bororo of Mato Grosso, and the Pomo of California.

Among the Arunta anthropologist Thomas Penniman writes that, “Stone and wooden bullroarers, which are the receptables of the spirits of all the Arunta who have been, are, and will be...The bogey Twanyirrika is a pure fiction used by the men to explain the noise of the bullroarer to women and uninitiated boys,” while among the Bororo anthropologist Stephen Michael Fabian says that, "Uninitiated boys and all females risk death if they see the aije [spirit entity], whose distinctive sound is replicated by the bullroarer. With their iorubodare [initiation sponsor] leading them onward and chased from behind by the menace of the aije whose eery and awesome whirring can be heard for several kilometers, the youths literally “run” or “flee” for much of their training."

Among the Mbuti anthropologist Colin Turnbull says, “The sound of the bull-roarer, a piece of wood that makes a strange whirring noise when spun around on the end of a cord, was meant to be the voice of a forest demon, and the boys had to show due respect and terror when they heard it,” though this practice was influenced by nearby Ituri villagers, and in their own molimo ceremonies Mbuti men use a trumpet (off-limits to women and children) rather than a bullroarer, to embody an animal spirit.

Finally, of the bullroarer among the Pomo, anthropologist S.A. Barrett tells us that,

It resembled the sound of thunder, and was made purposely to imitate thunder. One informant stated that in ancient times the bull-roarer was used primarily in the Thunder dance (kalī'matōtō ke), a dance participated in by men only. The bull-roarer was used only by the head man of this dance, and then only at night. The conception was that it was actually the voice of Thunder himself. The informant expressed it as follows: canē' mīnaū tcadō'dūn nan cītin tcanō'ngan. dance house on top picked up and swung around made talk. The bull-roarer was considered to be a sacred object. It could be manufactured only after proper ceremonial procedure, and the maker had to go out into the woods at some distance from the village and there make a sacrifice. In olden times, women or children were never permitted to see a bull-roarer. As above mentioned, it was used only at night and was kept carefully hidden away at all other times.

What to make of these practices? Modern scholarship in evolutionary biology and the cognitive sciences offers some hints. In their 2018 Cell paper ‘Form and Function in Human Song’, Mehr et al., write that,

Research from across the biological sciences demonstrates that the features of auditory signals and other communicative behaviors are shaped by their intended outcomes. For instance, as a general principle, low-frequency, harsh vocal forms with nonlinearities are expected to function in signaling hostility because those features are correlated with increases in body size and larger animals tend to defeat smaller animals in conflicts.

This point about low-frequency, harsh sounds with nonlinearities being expected to function in signaling hostility provides us with a useful framework for understanding the intimidating mimicking of powerful spirit-beings accomplished via the bullroarer across various societies. This idea is also consistent with previous research on this topic. In his cross-cultural survey of bullroarers in his work The Study of Man (1898), anthropologist Alfred C. Haddon writes that, "The weird sound of the whirling bull-roarer is suggestive of unseen forces, and so it naturally becomes associated in men's minds with spirits or ghosts,” while J.D. Harding, in his survey of ‘The Bull-Roarer in History and Antiquity’ (1973), notes that “Such sounds would appear to be ideal for the purpose of the operating bull-roarer in former times, when, inter alia, it was required to inspire awe, to suggest the supernatural, to scare and to terrify.”

Haddon’s (1898) data on the distribution and function of bullroarers across geographic regions exhibits some important similarities and differences with my own findings. Each of our data indicate some societies using bullroarers for weather manipulation in North America, as a children’s toy among the “Eskimo” [Inuit], sacred mysteries involving spirit beings in Australia and parts of Africa, and being taboo to women in Australia and parts of Africa and South America.