Spinning apes

When I was younger, I liked to spin, and took any opportunities I could get. Merry-go-rounds at the playground, spinning on a swing or even just spinning in place and then suddenly stopping to stumble to the ground laughing.

For children the “funny feeling” of a spinning head and loss of balance may be the goal of play. However, in some careers, adults have to learn how to prevent it and practice a lot not to lose their balance after pirouettes in for example ballet or figure skating. On the other hand, Sufi whirling dervishes traditionally spin to reach a state of mistic experience and spiritual trance.

When we quickly turn around our axis, the signals from our inner-ear organ (which is responsible for sensing changes in body motion and orientation) are disrupted and not in line with the signals sent from our eyes. This leads to a perception of a spinning world, dizziness, light-headedness, vertigo and other altered states.

It seems that the willingness to reach such mental states by spinning is not unique to humans. Recently researchers analysed many YouTube videos of great apes to compare their spinning rate and duration to that of professional human “spinners” (dancers, acrobats and whirling dervishes).

All species of great apes (chimpanzee, bonobo, gorillas and orangutans) engage in spinning. Researchers focused on rope spinning which seemed to be a solitary play activity without any goal beyond the act itself. Animals turned around their axes holding hanging ropes (or similar objects) with their hands and/or feet or even teeth. Sometimes they didn’t touch the ground at all while spinning.

Their spinning speed is similar to that of people that spin professionally and induces dizziness in untrained people (you can try it yourself*). Contact with the ground was associated with slower turning but allowed for more continuous revolutions.

There were some differences between species. For example, orangutans spun faster than gorillas and used a different technique – used a foot grip often, while gorillas never. This difference may stem from the differences in their lifestyles in the wild. Orangutans live in trees, and gorillas mainly on the ground. It would be interesting to see whether they are also different in how dizzy they get from spinning.

The inner ear of great apes is built similarly to ours and they have a similar body size which suggests that their experiences during and after spinning are also similar to ours. They indeed sometimes seemed dizzy after a spin – they immediately let go of the rope, sat or laid down, or walked a couple of steps and sat down. Although at other times they didn’t seem to be affected at all.

Animals were observed spinning on ropes not only in captivity but also in the wild. But it is unclear how often they do so in natural conditions, and whether there are differences in the frequency of this activity between the species, age groups or sexes. But for sure rope spinning is not confined to great apes (humans among them) as gibbons and monkeys were also observed doing it.

When did you spin last time? Maybe it’s worth returning to childhood games? 

* On average great apes span 5.4 revolutions per bout for and average of 3.3 consecutive spinning bouts with an average speed of 1.43 revolutions per second (rps). The longest observed bout consisted of 28 revolutions. The fastest sustained speed (for five spins) was 3.3 rps and the fastest single spin: 5 rps.

You can find more links to films of spinning apes in the supplementary material for the original article.

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Photo: Schorsch from Pixabay

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