Tiffany O'Callaghan

From individual water use to lessons from past civilisations, here’s what our Parched Earth series revealed about the impact of the megadrought in south-western North America

US president Joe Biden announced a pardon for thousands of people convicted for possession of marijuana under federal law

How much of our make-up is predetermined by our genes, and how much by our environment? The truth is that we’re asking entirely the wrong question

Robert Lustig’s hunch about obesity evolved into a war against sugar and the food industry. His battle for change has attracted controversy as well as praise

People with misophonia find sounds like rustling paper or clacking keyboards deeply distressing. Now scans have revealed differences in how their brains work

Forty years ago, Peter Piot raced to the scene of an outbreak of an unknown deadly disease. What he discovered gave him his life’s purpose

Digital technology is transforming the way we read and write. Is it changing our minds too – and if so, for better or worse?

You could win a bookshelf full of beautifully bound, iconic works of science and natural history simply by telling us what purchase made you happiest

It has been called toxic, addictive and deadly, the driving force behind obesity, heart disease and diabetes. Is sugar really so bad, asks Tiffany O’Callaghan

Our crudest outbursts can unravel ancient links between words and thoughts. They may even hint at our ancestors’ first utterances, finds Tiffany O’Callaghan

Your dulcet tones affect everything from your sex appeal to your bank balance. But they can also wildly misrepresent you, finds Tiffany O’Callaghan