People lie - usually several times a day. Lying is considered immoral, but we've been built for it. And we are not alone. Dishonesty is an integral part of the social world, and numerous animal species are also skilled deceivers.
People lie between two and 80 times a day. That may sound like a lot, but not all lies are equal. White lies are often a means of being polite, or of not offending someone. They help lubricate social interactions, and maintain harmonious coexistence. Black lies, on the other hand, are told with the intent to deceive, or for self-interest. Scientists have discovered that the brain actually adapts to dishonesty. The more someone lies, the less that person’s brain reacts. But humans are not the only species capable of dishonesty. Many animals also cheat. Especially social animals, such as pigs. Scientists from the University of Veterinary Medicine, Vienna, have been researching dishonesty among pigs, and found interesting results. Indeed, it seems that lying and cooperation evolved in parallel. When it comes to humans, children as young as five are already capable of cheating. We tend to think that dishonesty is immoral, but the ability to lie signals healthy cognitive development in children. Scientists have long been searching for a way to reliably detect lying. This would be an asset in criminal investigations. However, classic lie detector tests, which measure pulse, heart rate, respiration, and skin conductance are inaccurate. But a scientist in Germany has managed to devise a questioning technique with which he is achieving surprisingly accurate results with a lie detector. And researchers in Granada have found that a person’s face and hands change temperature when they are lying. So can dishonesty be reliably measured using a thermal imaging camera?