Ever wondered why your friend can function perfectly well on significantly less sleep than you? Well, your genes might provide you with an answer, according to new research. Former British Prime Minister Margaret Thatcher once claimed that she lived on a measly four hours sleep each night, while legendary physicist Albert Einstein admitted that he needed at least 11 hours, illustrating how some people need more rest in their double beds than others. In a joint-study of more than 10,000 Europeans by researchers at Edinburgh University and Ludwig Maximilians University in Munich, a new form of gene was discovered and evidence found to suggest it influenced the amount of sleep we need. The gene, named ABCC9, is responsible for sensing the human body's energy levels. The gene patterns of those surveyed were investigated alongside the individuals' sleeping habits, and those who exhibited two copies of the gene were found to spend more time in bed than their counterparts with just one copy. Dr Jim Wilson of Edinburgh University said of the findings: "Hopefully more genes will now be discovered and this can also lead to us dealing better with the connected health issues."