Download the Nature Podcast 28 August 2024

In this episode:

00:31 Chatbots make racist judgements based on dialect

Research has shown that large language models, including those that power chatbots like ChatGPT, make racist judgments based on users’ dialects. When asked to describe a person, many AI systems responded with racist stereotypes when presented with text in African American English—a dialect spoken by millions of people in the United States and associated with the descendants of enslaved African Americans—compared to text in standard American English. The results show that such models harbor covert racism even when they do not display overt racism, and that traditional solutions to remove bias in these models have had no effect on this problem.

Research articles: Hoffman et al.

News and views: LLMs produce racist results when asked to do so in African-American English

Nature News: Chatbot AI makes racist judgments based on dialect

07:01 How ancient engineers built a megalithic structure

The 6,000-year-old Menga Dolmen is a marvel of ancient engineering. Research has now revealed new insights into the structure and the technical skills of the Neolithic builders who constructed it. The work shows that an arrangement of counterweights and ramps may have been used to correctly position the massive sandstone blocks that make up the walls of the structure. Each of these blocks was tilted at precise, millimetre-accurate angles. The researchers say this design shows that the Neolithic people who built the dolmen had a thorough understanding of physics, geometry, geology and architectural principles.

Nature News: Study of a 6,000-year-old monument shows that Stone Age builders had technical skills

12:28 Spider lets fireflies flash as bait

Orb-web spiders (Araneus ventricosus) use caught male Absocondita terminalis Fireflies to lure more insects into their web. A bite from the spider causes the captured firefly’s flashing pattern to change, resembling that of a mating female luring others into an ambush. Exactly how this system works is unclear, but researchers say it’s a rare example of a predator altering the behavior of its prey to catch others.

Science: Spiders force male fireflies to blink like females – and thus lure more males to their deaths

16:35 The physics of paper cuts

By combining experiments and theoretical work, a team has solved the mystery of why only certain types of paper can cut human skin. Their work shows that paper that is too thin bends without cutting, while paper that is too thick spreads the force over a relatively large area without causing damage. The research suggests that the optimal point for cutting is paper that is around 65 microns thick, which includes the kind used to print certain high-profile magazines…

Research highlight: What Science And Nature are good for: paper cutting

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