UU professor wins Ig Nobel Prize for studying underpants-eating microbe

Alongside colleagues from Switzerland and Germany, Marcel van der Heijden won the Ig Nobel Prize thanks to his soil research, which involved burying 2,000 pairs of underpants. The UU professor accepted the prize dressed as an underpants-eating microbe. 

The Ig Nobel Prizes are a parody of the Nobel Prizes. They are awarded a month before the actual Nobel Prizes are announced, during a funny ceremony full of costumes, music and interrupted speeches. This year's winners threw underpants into the audience, who had previously thrown paper aeroplanes onto the stage.

The study by Van der Heijden and colleagues showed that soil use determines the rate at which materials – in this case, underpants – decompose. “The decomposition process occurs much faster in gardens than on lawns or any other place where there is little activity in the soil,” explained Van der Heijden in an interview with the Dutch newspaper De Volkskrant.

The scientific article that resulted from this study details its importance. “Burying underwear is a simple and easy-to-interpret method for gaining an initial impression of soil conditions.” In addition to gathering information about soil health, the researchers were motivated by a desire to raise awareness of soil conditions. After all, soil health is vital for our food system. 

Non-scientists buried 2,000 pairs of underpants in 25 countries. After two months, they dug up the underwear again.

Another winner
The Ig Nobel Prize for Biomechanics went to a study that arrived at a new definition of kissing, which could be applied to ants, birds, polar bears and humans. At the award ceremony, the winners kissed "cave dwellers" on stage.

Stealing sweets
The Ig Nobel Prizes also awarded an economic study on class differences that found people from the upper class are more likely to steal sweets from children’s stashes and exhibit other unethical behaviour.

Cockroach milk
Furthermore, scientific research revealed that a viviparous cockroach's milk contains three times as much energy as cow’s milk. Scientists also discovered that mosquitoes' proboscis could be used as a nozzle for 3D printers. In addition, they found that parents like how babies smell but do not like how teenagers smell. Last but not least, science has shown that we like our friends more if they are occasionally mean towards people we consider stupid.

First ceremony in Europe
This is the 36th edition of the Ig Nobel Prizes. The award ceremony took place in Zurich this time. It used to be held in Boston, but the organisers have decided to leave the United States because they believe academics there have little left to laugh about. “We cannot in good conscience ask this year’s new winners and international journalists to travel to the US,” the organisers stated.

Trump
The situation in the United States was not mentioned during the ceremony. However, the Dunning-Kruger effect was celebrated against the backdrop of a photograph of the US President, Donald Trump. The Dunning-Kruger effect is the psychological phenomenon whereby incompetent people often overestimate their own performance, precisely because of their incompetence. 

Watch party
Paper aeroplanes were also flying about during the official watch party held at Utrecht Science Park on Thursday evening, where UU researchers and students gathered to watch the awards ceremony on a big screen. Before the ceremony in Zurich began, a few scientists from Utrecht University shared stories about their own "Ig Nobel Prize-worthy" research.

“I had never disappointed so many people in my life,” said UU biologist Monique de Jager, laughing. For a study on plant seed dispersal, she investigated how many plants would grow if pots without seeds were put outside. The answer: not many. A school class taking part in the research withdrew from the project; that's how disappointed they were.

Utrecht University gathers to watch the 2026 Ig Nobel Prizes. Photo: DUB

Andreas Voss, a professor of Infection Prevention at Nijmegen University and winner of the Ig Nobel Prize in Economics, attended the watch party in Utrecht. He and his son, who is a PhD candidate, investigated the chances of bacteria surviving on banknotes. These chances turned out to be particularly low on the Croatian kuna. For anyone worried about touching infectious banknotes, Voss has a solution: “Just give them to me.”