Andrew Balmer, a senior lecturer in sociology at Manchester University who has studied lie detection, says any attempt to find a truth is inherently political. “Lies can become habitual and automatic, especially if we tell them frequently, or we practice them,” he says. “So lie detection is scientifically and sociologically invalid. Any attempt to objectively determine whether someone is lying is doomed to fail.”"There are many cases in the USA, where the polygraph machine is used widely, of serious injustices resulting from this kind of interrogation," he adds. "We have done well in the UK and in other parts of Europe to keep lie detection out of our justice system. We shouldn't let it take hold now."