Appliance of science: Why do we lie?

We Irish can be great for enhancing a tale. As natural storytellers there is nothing wrong with a little embellishment, is there? But what is the difference between a little exaggeration and a full blown lie?

WHY DO WE LIE?

Let’s get this out of the way first, we all do it. From the little white lies to the great big whoppers, we all tell one from time to time. Sometimes we do it for good reasons, sometimes just to save our skin. So why do we do it and is it a purely human activity?

We lie for a number of reasons, it may be a little white lie to make someone feel better or it might be a big lie for our own gain.

Often we lie to present a better side of ourselves; we may not even realise we are doing it.

We probably lie because evolution has shown it to be a good thing; it can benefit both ourselves, as individuals, and society. Our abilities to lie have grown with the development of our social connections. It can be a valuable thing and brings with it many advantages.

Lying is a sign of intelligence and is considered a complex cognitive skill.

WHAT HAPPENS IN OUR BRAINS WHEN WE LIE?

Lying is not easy; in order to do it correctly we must focus our brains on two completely different pieces of information, the lie and the truth.

We can only really deliver a lie well if we convince ourselves it is true. Lying is a much more taxing process for the brain.

Activity in the prefrontal cortex (at the front of the brain) has been shown to increase when a person lies. This is the part of the brain involved in decision making, problem solving and cognitive planning.

Usually when we tell a small lie, for personal gain, we feel bad. These emotions of regret and guilt are controlled by a part of the brain called the amygdala. However, the more we lie, the more we desensitise the amygdala so that it produces less of these bad feelings.

Pathological liars have apparently 25% more white matter in their prefrontal cortex, suggesting more connections between different parts of the brain. However, they also have about 14% less grey matter, the part that can help rationalise the potential consequences of each lie told.

DO OTHER ANIMALS LIE?

It seems that some do. A famous example is that of Koko the gorilla. Koko is renowned for her sign language abilities with an impressive vocabulary of more than 1000 words. She had a pet kitten that come in handy for more than just cuddles and companionship. Like when she tore a sink from a wall in her enclosure; when her carers returned and asked what happened, Koko signed ‘the cat did it’.

WHEN DO WE START LYING?

Some scientists believe that deception begins as young as six months old. This usually starts as fake crying to get attention. At that age it is more of an unconscious act but by the age of two we have developed the skill quite a bit and are capable of more direct lying.

It is estimated that adults lie, on average, about 10 times a day. Studies have shown that we can lie about three times in one short conversation with a complete stranger.

Naomi is a science communicator and mother to three inquisitive children. She can be found at sciencewows.ie

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