Why do we lie?

Why do we lie?

I watched a great documentary on Netflix* recently all about lying… it is called Dis(honesty): the truth about lies and I would highly recommend it.

It really got me thinking about lying, why do we do it, what would happen if we don’t and is it a uniquely human activity?

First off, we all do it! If you are shaking your head in disagreement, then you’ve just lied too! Sometimes we do it for good reasons, sometimes just to save our skin, but we all lie from time to time. 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, or to save our skin!

Many of the lies we tell are to present a better side of ourselves; make ourselves appear a little nicer, a little smarter, or a little more popular. We don’t often even recognise these lies, we don’t realise we are doing it – we are lying to ourselves!

On a base level, we probably lie because evolution has shown us that it works to our benefit and the benefit of society. As our social connections have developed, so too have our abilities at lying. It is actually a valuable tool to have and brings with it many advantages. Lying is a sign of intelligence and is considered a complex cognitive skill.

Different types of lies and liars

There are different types of lies and different categories of liars! There are the little white lies that we all do, usually for social acceptance or compliance. There are lies of exaggeration, usually of little harm either;  and then there are the bigger lies that are often more serious and come with a lot more consequences if found out.

There are also different types of liars. We are all contributors to the pool of common-or-garden, everyday liars, but things get more serious when we look at the compulsive or pathological liar.

Compulsive liars tell lies as the norm, it is an automatic reflex and it takes a lot less effort for them than telling the truth does. Pathological liars tend to take it one step further; they lie for their own gain, with little thought to the consequences of their lies, for either themselves or others.

What happens in our brains when we lie?

Lying is a complex process; in order to do it our brains must focus on two opposing pieces of information at the same time: the truth and the lie. If we want to process or deliver a lie we need to believe that it could be true. The brain has to work much harder to lie than to tell the truth. 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, cognitive planning and problem solving.

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 desensitize the amygdala so that it produces less of these bad feelings.

Studies on the brains of pathological liars show that they have about 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.

No man has a good enough memory to be a successful liar- Abraham Lincoln

Do other animals lie?

Yes some do. One famous example that my children love to hear about is of Koko the gorilla. Koko is renowned for her sign language abilities, with an impressive vocabulary of more than 1000 words. Koko has a pet kitten that has come in handy for more than just cuddles and companionship. One day Koko tore a sink from a wall in her enclosure. When her carers returned and asked what happened, Koko signed ‘the cat did it!’

Koko The Gorilla2

When do we start lying and how often do we do it?

Some scientists believe that we begin the act of deception as young as six months old! This usually starts as fake crying, or smiling, to get attention. At that age we don’t do a very good job (although it is probably quite cute and amusing to watch) and we likely do not do it as a conscious lie.

By the age of two however, we have put in a little more practice and can deliver an outright lie with more commitment and conviction.

Adults are so good at lying that they can often lie even to themselves; on average, adults lie about 10 times a day and we can throw about three lies into a short conversation with a stranger, without even knowing we are doing it.

Are there ways to spot a lie?

Some of us are better liars than others and there is no detection system, including lie detectors, that work for all. However, many of us amateurs give away some tell-tale signs when we are lying, such as…

  • We make and keep direct eye contact (contrary to common held belief)
  • We keep our bodies very still, but we may…
  • jerk our heads a lot
  • We give more information than is necessary
  • We touch or cover our mouths with our fingers
  • We breathe at a more rapid rate
  • We cover vulnerable parts of our bodies, such as the throat, head or chest

Interestingly, we are better at lying when we lie for altruistic reasons than for our own good and these lies are more difficult to detect.

So that is the low-down on lying, and not a word of a lie 😉

Have you any facts or stories to add? I’d love to hear them, just leave them in the comments below.

*Disclosure: As a member of the Netflix Stream Team I have received a years subscription to Netflix, free of charge, and an Apple TV, for streaming purposes. As part of Netflix Stream Team I will be posting monthly updates on what we are watching and what is on offer.  All opinions expressed will be my own.

How high do birds fly?

How high do birds fly?

This question comes in from twins Sabha and Lile, who can sometimes be found on the lovely Where Wishes Come From blog. They are two wonderful girls that are fairly mad into science, and their mum tells me that they are always full of questions (we love that around here!). This is the first of two questions they have sent in…

How high do birds fly?

Dr. Simple is, as ever, delighted to answer their question. And this week he has his twin sister with him (which is pretty appropriate don’t you think?).  You’ll see below that the regular Dr. Simple post has had a revamp, I love it like this, I hope you do too!



Thanks again to Lile and Sabha for this great question, what super science twins you are!

I hope you like the new layout here, be sure to let me know in the comments below, and remember to send in any questions that you or your family have. We love getting them!

Do we have the most dependent offspring?

Do we have the most dependent offspring?

Our garden is bursting with life at the moment!  Busy, haggard birds are flitting around, building nest and laying eggs.  Insect populations are slowly emerging and even our hens are getting broody!  For the first year ever we have a number of young rabbits joining in the ecosystem that is our back garden.  The rabbits in particular have attracted the children’s attention.  You can understand why… there must be at least five of them and they are very tiny, very cute and very independent!  That got my children wondering….

photo credit: Gidzy via photopin cc
photo credit: Gidzy via photopin cc

Rabbits are independent from a very early age.  A female rabbit (called a Doe) will give birth to a litter of four to twelve baby rabbits (called Kits).  The kits are born blind and without any fur.  However within a week their eyes have opened, their fur begins to grow and their ears begin to stand upright. Wild rabbits will begin to wean about two weeks old and within three weeks they have grown enough to leave the nest and live independently.  They may look small and helpless in our back garden but they are old enough to go it alone in the wild.

A doe can reach sexual maturity between three and six months and can live for up to ten years.  The breeding season of rabbits usually last three quarters of the year.  The most amazing aspect of the rabbit though, is that fact that the doe has no oestrus cycle.  She can literally get pregnant a day after giving birth. Her gestation period is only one months long.

If you want to do the maths on all that it means that one doe could give birth to up 80 to 100 kits a year, or as many as 1,000 kits in one lifetime.  With these turnover rates you can see why the kits have to be independent pretty quickly!



photo credit: Harpersbizarre via photopin cc
photo credit: Harpersbizarre via photopin cc

The busiest members of the garden seem to be the birds.  Nest building, egg laying and then feeding a brood of hungry and demanding chicks.  For the first part of their lives these chicks are completely dependent on their parents for food and the parents spend the early summer months on a non stop conveyor belt of foraging and feeding.  The chicks learn to out “beg” their siblings rather than how to feed themselves.  Of course this does not last for long, eventually these young birds will learn to fly and forage all by themselves … no mean feat!

Why do birds choose to feed rather than encourage foraging at an earlier stage?  By evolving in this manner birds can choose to build their nests in more isolated, out of reach places, such as high up trees or on cliff edges. The compromise is that such places do not have a ready supply of food so the parents must go and source the food and bring it back.  Although an exhausting process, the chicks are more likely to survive!



This one depends on the insect obviously.  Most insects’ parenting work ends with the lay of their eggs.  This they usually do in large quantities, to increase the chances of survival of at least some of their progeny.  Once the young hatch they are on their own!  Often having to work their way through a number of different forms and changes before they even make it to adulthood! Imagine what it must be like to morph from a grub to an adult? Must be like going through your teens without any parental guidance what so ever!

Not all insects leave their young to their own devices of course.  Some bee, wasp and ant species tend to the eggs in colonies of nests or hives.  Once the larvae emerge from the egg they are fend and tended to completely, passing through different developmental stages until they pupate and emerge as adults.



The  insects and birds mentioned above rely on their young doing most of their development outside the adult body, in eggs and/or larval stage.  They are not mammals (giving birth to live young) like rabbits or humans.  We have seen how quickly the rabbit young develop and gain independence from their mother.  This is not the case with human infants though.  So why the big difference between the dependence of the young in rabbits and humans?

Factors that influence the level of dependence of young on the adult can include

  • size of the fetus
  • size of the mother
  • number of young per birth
  • brain size and growth rate
  • cultural behaviour of the species
  • life span

Rabbit have large litters, short gestation periods, a less developed brain and a shorter life span than humans.  These facts all explain the difference in dependence of young.

If we look at all mammals we find that humans have very dependent young relative to most other species.It is thought that our evolution into bipedal (walks on two legs) creatures has meant that our young must be born with smaller brains and that the brain develops more after birth.  This is for physical reasons: in order to walk upright the size of our pelvis is restricted and therefore the size of the infants we give birth to is restricted.

To examine infant dependence even further we can compare the dependence of human young with those of other primates; Human infants are much more underdeveloped at birth than their primate relatives!  In fact human development is thought to take 30% to 50% longer than that of other primates.  Why is this the case?  Perhaps it goes back to the point that life span may play a role in infant dependence?  This point alone does not account for the big difference observed between humans and other primates.  Other suggestion that might contribute are the nutritional demands on the mother during gestation and the amount of growth and development the brain will undergo after birth.

Scientists are now also looking at the contribution of maternal nurture and the cultural development of the society of the species.  Humans have evolved a highly developed social and cultural environment.  We have developed complex communication methods (e.g. language and social ques) and cultural interactions.  In order to fit into such a complex system, perhaps the human infant must learn by observation and inclusion… neither of which it can do in the womb.  Maybe we are born with such underdeveloped brains because most of our development and learning can only be done in the culture within which we will live!

What do you think?…..