Enemas are used today for health reasons, like purging your blocked plumbing, but back in the day of the ancient Maya, they were used for something much more fun.
That's according to one of the winners of this year's Ig Nobel prizes.
The Ig Nobels are satirical prizes for scientific achievements that "make people laugh and then think".
They're organised by US publication the Annals of Improbable Research for legitimate research in areas including biology, medicine, physics and social sciences.
Winners were awarded a fold-up paper prize and an old (and basically worthless) Zimbabwean $10 trillion note today during an online ceremony.
One particularly probing piece of research came from the winners of the Ig Nobel Art History Prize, who analysed scenes on ancient Mayan pottery, such as vases and jugs from the 6th to 9th centuries.
Scenes depicted on the pottery, found in countries like Guatemala and Mexico, include ceremonies with people dressed as animals such as jaguars, deer or monkeys.
And in some scenes, inebriated people are seen being held up by others.
"In the scenes on the pottery, they're getting high and they're getting drunk," prize recipient Nicholas Hellmuth said.
"These are people having fun in the royal palace on Friday and Saturday nights."
Lurking in the artwork is evidence that the Maya ritually used enemas to make the most of their drugs of choice.
"They're taking the enema to get alcohol and hallucinogenic drugs into their body more easily than drinking them," said Dr Hellmuth, who is from the Foundation for Latin American Anthropological Research.
In some pottery scenes, people are seen receiving an enema from another person, while in others they are administering it to themselves. But whatever the case, this is not some private affair.
"This is a ritual that is carried out in public," Dr Hellmuth said.
Dr Hellmuth shares the prize with retired ethnopharmacologist Peter de Smet, who first documented evidence of enemas being used for recreational and ritual purposes for his PhD in the 1980s.
"This idea is quite contrary to the traditional view that the ancient Maya were a contemplative people, who did not indulge in ritual ecstasy," reads a 1986 article Dr de Smet wrote with Dr Hellmuth.
While the 1986 paper suggested water lily may have been used as a hallucinogen, following a 2020 update of his research, Dr de Smet now argues the most likely hallucinogens used were made from Ipomoea corymbosa (morning glory seeds), or parts of datura, a plant with white flowers also known as "devil's trumpets".
Dr Hellmuth notes, however, that the water lily is the flower most commonly pictured in classic Mayan art.
Clever ducks
From enemas to energy saving, and the Ig Nobel Physics Prize goes to research that explores why exactly ducklings swim in formation behind their mother.
Frank Fish, a professor of biology at West Chester University in Pennsylvania, measured the oxygen consumption of mallard ducklings and concluded swimming behind their mum took less effort than if they swam out of formation.
Professor Fish argues the physics at work is the same as that involved when cyclists "draft" or "slipstream".
As the front-runner slices through the air, the air flowing around them, a low-pressure area forms in their wake, and if someone behind can get close enough, they can be hauled along.
When it comes to ducklings specifically, Professor Fish said a straight line or diamond formation directly behind the mother was the best.
And he found the longer the string of ducklings, the more advantage to the last in the line.
"They could essentially just coast behind everyone," Professor Fish, who even drew a cartoon to illustrate the fact, said.
His work (published in 1994) wins the prize along with 2021 research that used computer modelling to conclude ducklings in formation are, in fact, surfing behind the mother.
"We have to experiment a little bit more to find out which might really be the case," Professor Fish said, adding that both processes could be at work.
But he was over the moon at winning an Ig Nobel.
"This is something I've always dreamed about," said Professor Fish, whose email signature reads: "You're not doing science if you're not having fun."
Decoding legalese
What's not much fun is reading a legal contract.
To that end, the Ig Nobel Literature Prize went to a team that just this year provided quantitative evidence of what makes legal documents notoriously – and unnecessarily — difficult to understand.
The researchers analysed and compared the content of legal contracts and other documents, ranging from academic papers to newspaper articles, and then looked at how well people understood them.
They found that it was not the complexity of concepts that was the problem, but rather "a startlingly high" proportion of writing features that are hard to process.
One of the main culprits were subclauses, embedded in really long sentences.
Take something like this:
In the event that any payment or benefit by the Company, all such payments and benefits, including the payments and benefits under Section 3(a) hereof, being hereinafter referred to as the ‘Total Payments’, would be subject to excise tax, then the cash severance payments shall be reduced.
"Legal documents had over two times the number of centre-embedded clauses than any other control text we looked at," said team member Eric Martínez, a PhD student at MIT's Department of Brain & Cognitive Sciences.
The other major culprit making legalese so hard to understand was jargon that could be easily replaced with everyday common alternatives.
These included Latin phrases like "ab initio" meaning "from the beginning" and "ex post facto" instead of "after", as well as "lessee and lessor" instead of "tenant and landlord", and "hereinafter" instead of "before".
"The words in legal documents were more than twice as obscure as the words in Wall Street Journal articles, and 25 per cent more obscure than the words in academic journal articles," Mr Martínez said.
The team has also run the same experiment – as yet unpublished — with lawyers, he added.
They found while the "experts" were generally better at understanding legal documents than non-lawyers, they still found legalese harder to understand than other writing styles.
Another study from the team – also yet to be peer-reviewed — suggests legalese has not changed much over the years, and in some cases, become worse.
"So much for plain language," they quipped in the title of their pre-press article.
Romance synchronises our hearts
Something that is much more fun is falling in love.
The Ig Nobel Applied Cardiology Prize went to research that last year did some pretty heavy-duty monitoring of people's physiology on a blind date.
"Participants wore eye-tracking glasses with embedded cameras and devices to measure physiological signals including heart rate and skin conductance," reads the paper by Eliska Prochazkova of Leiden University's Institute of Psychology, in the Netherlands, and colleagues.
"We found that overt signals such as smiles, laughter, eye gaze or the mimicry of those signals were not significantly associated with attraction."
Instead, they found attraction was predicted by synchronised heart rates, and another feature called "skin conductance" – an indirect measure of emotion.
These are both factors that you would not notice, are unconscious, and difficult to regulate, the researchers wrote.
"Our findings suggest that interacting partners' attraction increases and decreases as their subconscious arousal levels rise and fall in synchrony."
The art of gossip
And so to the question of whether we lie or tell the truth when we gossip.
The winners of this year's Ig Nobel Peace Prize are a team that last year developed a mathematical model that determines when gossipers are honest or dishonest.
People lie to help allies and harm competitors, both of which are good for an individual, said Australian team member Kim Peters, who is a management professor at the University of Exeter.
"We want to say nice things about those we care about and nasty things about those we dislike, and if it's not possible to do this honestly, we can simply lie about what they've done," Professor Peters said.
"In addition to this, we want to give good advice to people we care about by giving them honest gossip, and bad advice to people we dislike by giving them dishonest gossip."
Understanding such dynamics can help people decide whether to trust gossip or not, Professor Peters added.
Of course, sometimes there can be a conflict: like when you're talking to a friend about another friend who has behaved badly.
"Telling the truth will help your friendly audience, but hurt the friend you are talking about. Lying will have the reverse consequence," she said.
"In these situations, gossipers face a trade-off, and should aim to help, by telling the truth or lying, about whoever they care about most."
