Source: Erik-Jan Leusink on Unsplash Liking a lie-in in people's genes, researchers say People who like a lie-in may now have an excuse - it is at least partly down to their genes, according to experts. Experts, who studied more than 10,000 people across Europe, found those with the gene ABCC9 need around 30 minutes more sleep per night than those without the gene. The variant is carried by one in five Europeans, they say in their study, published in Molecular Psychiatry. + The researchers said the finding could help explain "sleep behaviour". Over 10,000 people took part, each reporting how long they slept and providing a blood sample for DNA analysis. People's sleep needs can differ significantly. At the extreme, Margaret Thatcher managed on four hours of sleep a night while Albert Einstein needed 11. Fruit flies People from the Orkney Isles, Croatia, the Netherlands, Italy, Estonia and Germany took part in the study. All were asked about...