PARIS - One recent Sunday afternoon, a father sits on a park bench reading his magazine; all the while watching his six-year-old son Sébastien out of the corner of his eye, as he plays on the seesaw with the other children of his Parisian neighborhood.

One of the children runs back to his mother, followed by Sébastien, who isn't shy and starts talking to the adult, whom he doesn't know. His father distractedly half-listens to his son's babbling; however, he quickly reacts when he hears him telling the woman that no, the man next to them whom she saw arrive with the child, is not actually his daddy.

The father jumps right up, angry, and grabs his son by the arm, asking him for an explanation. Why did he lie to the lady? The boy wriggles, simpering, but he can offer no explanation as to why he said such a thing to the woman – leaving his father at a loss, and in a foul mood.

Discovering that one's child is telling lies - or hiding things and keeping secrets - is always worrying for parents. Up until this moment, they have been convinced that they have total control over their children. Confronted with the lying, they feel that they are losing control: a feeling that will only grow stronger as their children grow older. The discovery of these little white lies are hard to swallow, as we feel betrayed and disappointed.

Yet, having secrets, even if it means lying in order to keep them, is essential to children's personality development and their mental equilibrium. One study, undertaken by Valérie Aubron, entitled Pathological lying in children: A psycho-developmental approach, which was published in Annales médico-psychologiques in 2007, showed that 60% of girls and boys aged from six to eight "occasionally" lie, while 20% do so "frequently."

Giving children this right is to consider them "a well-rounded and independent individual, who can fully interact with his parents," underlines the clinician and psychotherapist Dana Castro, the author of Petits silences, petits mensonges Little Silence, Little Lies. In general, children lie because of three things: to avoid punishment, to assert their personality and to protect people that they love. Numerous psychological experiments and studies have shown that children are capable of lying, which means that they can deliberately distort reality from a very young age. From the age of four, they discover that far-fetched lies can be used in order to get what they want, or to protect themselves from things that they fear.

Pretending that it was the cat who nibbled the side of the birthday cake, for example, is a way of escaping punishment. Children live in a universe filled with stories and legends - Father Christmas and the Tooth Fairy, for example - which adults feel the need to keep up, and feel more and more awkward about breaking the spell.

That first little white lie

However, before the age of five, children do hesitate about lying, as they think that adults are able to read their inner thoughts too easily. This belief weakens progressively. "It only takes one little white lie that works in order for the child to realize that he possesses something very precious: his own personality, identity, and privacy, to which not even his parents can get access," says Castro. Escaping punishment through lying or not telling the truth leads to freedom and defiance.

"In order to lie, the child must be capable of empathy, which means that they have to feel emotions for the people around them, in front of whom they will hide or feign emotions," says the psychoanalyst and psychotherapist Pascal Neveu in his book Mentir, pour mieux vivre ensemble? Lying, to Live Together Better?.

Around the ages of seven and eight, children begin to realize that adults themselves bend the truth sometimes: either out of convenience, to avoid doing boring things, in order to spare someone’s feelings, to avoid an argument, or to enhance their image... So why can children not do the same?

When they begin secondary school, around the ages of 10 or 11, they start to feel detached from their parents. Their friends start to take a more important role in their lives; therefore, the need to fit in with the group sometimes leads to teenagers lying more frequently. At this age, the child knows perfectly well how to distinguish between little white lies -- which gets them out of doing household chores: "I can't set the table, I've got homework to do" -- and more serious deceit, which is capable of sabotaging mutual trust. Lies can also serve to mask reality, which is often too violent or difficult to accept. Denial is therefore a form of defense and a way of protecting themselves from real life.

As a teenager, the feeling of guilt tends to disappear. "The youth rejects parental values and no longer recognizes any adult authority," says Castro. Lying is therefore a way of asserting their freedom or autonomy from their parents, on whom they still depend, especially financially. Inevitably, the relationship becomes strained.

According to a British study entitled National scruples and lies survey, published in That's Life magazine in December 2004, teenagers tell a lie to their parents every other time they speak to them. It can become a habit, or even a reflex. Sometimes, teenagers even begin to lie to themselves, as a means of escapism or manipulation. This can sometimes be a call for help, and their family should intervene before this attitude starts to dangerously compromise the teenager's development and begins to ruin relations with others.