Skip to content Nature vs nurture: How much of our personalities are determined at birth? 23 hours ago Share Save Add as preferred on Google Laurie Clarke Emmanuel Lafont (Credit: Emmanuel Lafont) Laurie Clarke delves into the devilishly complex forces that shape our personalities – and the new research revealing ever more about how our genes do, and don't, make us who we are. In 2009, Abdelmalek Bayout faced a nine-year prison sentence in Trieste, Italy, for stabbing and killing a man who had mocked him in the street. Aiming to reduce the sentence, his lawyer made an unusual legal argument. His client's DNA, he said, indicated the presence of the "warrior gene", a mutation that decades of scientific research had tied to aggressive behaviour. Because of this, the argument went, he couldn't be held fully accountable for his actions. The appeal was successful: a year was sheared off Bayout's sentence. From the 1990s, evidence had accumulated ...