Great apes deliberately spin around in order to make themselves dizzy, researchers have discovered,
Academics at the University of Warwick and the University of Birmingham suggest the findings could provide clues about humans evolving the desire to seek altered mental states and actively manipulate their mood and perception of reality.
The study is based on the observations of online videos in which great apes – gorillas, chimpanzees, bonobos and orangutans – spin to deliberately make themselves dizzy.
Dr Adriano Lameira, associate professor of psychology at the University of Warwick who co-led the study, said: “Every culture has found a way of evading reality through dedicated and special rituals, practices or ceremonies.
“This human trait of seeking altered states is so universal, historically and culturally, that it raises the intriguing possibility that this is something that has been potentially inherited from our evolutionary ancestors.
“If this was indeed the case, it would carry huge consequences on how we think about modern human cognition capacities and emotional needs.”
The research team came across a viral video of a male gorilla spinning in a pool, and continued researching on YouTube.
They found more videos of gorillas, chimpanzees, bonobos and orangutans all spinning.
Forty online videos were analysed, and researchers found that on average the primates revolved 5.5 times per episode of spinning, with the average speed 1.5 revolutions per second.
The animals did this on average three times, the scientists found.
The spinning speeds were compared and the study found that the animals can spin while holding on a rope as fast as professional human dancers and circus artists, as well as Dervish muslims who take part in whirling ceremonies in order to achieve a spiritual trance.
Dr Lameira added: “Spinning alters our state of consciousness, it messes up with our body-mind responsiveness and coordination, which make us feel sick, lightheaded, and even elated as in the case of children playing in merry-go-rounds, spinner-wheels and carousels.”
He continued: “If all great apes seek dizziness, then our ancestors are also highly likely to have done so.
“We asked ourselves what role these behaviours play when it comes to the origins of the human mind.
“The apes were doing this purposefully, almost as if they were dancing – a known mechanism in humans that universally facilitates mood regulation, social bonding and heightens the senses and is based on rotation movements.
“The parallel between what the apes were doing and what humans do was beyond coincidental.”
In the videos where the animals were using ropes or vines to spin, they were spinning the fastest and for the longest amounts of time, the study found.
Some clips were compared with videos of purposeful human pirouettes, for example, ballet dancing, traditional Hopak dancing, whirling dervishes and aerial silks performances.
The researchers also tried spinning at these speeds and times themselves, and found it difficult to achieve the third bout of spins at these speeds, as great apes did.
Apes were noticeably dizzy at that point in the videos, and they were likely to lose their balance and fall down, according to the study.
Dr Marcus Perlman, lecturer at the department of English language and linguistics of the University of Birmingham who co-led the research, explained: “This would indicate that the primates deliberately keep spinning, despite starting to feel the effects of dizziness, until they are unable to keep their balance any longer.”
While past studies that attempted to understand human motivation for self-inducing dizziness focused on substance use such as alcohol or drugs, it is uncertain whether these or other substances would have been accessible to human ancestors.
Scientists say this new study could be more relevant to explain the role of altered states on the evolution of the human mind.
Dr Lameira said: “The further back in human history you look, the less certain we can be about the role that substance-induced experiences played in our evolution.
“It’s not clear whether our ancestors had access to mind altering substances, or if they had the tools and knowledge to create the substance.
“For example, people may have had access to grapes, but you cannot assume they have the tools or the knowledge to create wine.”
The researchers say further research is needed to understand the animals’ motivations for engaging in these behaviours.
The study is published in the Primates journal.