Even highly experienced lawyers and detectives cannot easily spot duplicity merely by observing people’s facial expressions and tone of voice. However, lying involves different brain areas from those used in telling the truth. We’re not there yet, but it is conceivable that in the not too distant future fMRI scanners could function as almost infallible truth machines. Where will that leave millions of lawyers, judges, cops and detectives? They might consider returning to school to learn a
