As children, my siblings and I were told by our mother that if you ever told a lie, your ears would turn black. She could therefore spot the lie immediately.
A stroke of genius really. Unless you are in front of a mirror, you really have no way to test this theory. This quirky, perhaps cruel strategy worked like a charm. Our Mum could spot the lie coming from a mile away. As we got older, we would attempt to cover our ears with our hands when confronting her about whatever the ‘crisis’ was. That did not seem to work either. A tell tale sign we were lying already.
As a parent now myself, I must admit I have used this strategy to my advantage. That is until my own kids figured it out for themselves. Their discovery of the truth involved purposely telling a lie while standing in front of a mirror and waiting for their ears to turn black. Truly a sad day when this happened.