The margay is a small wild cat native to South America. A few years back, biologists noticed a strange behaviour being displayed by this tree-dwelling animal. They found out the feline was imitating the call of a baby monkey. They conducted some studies and found out that the margay’s imitation game was a clever ploy to lure its prey - adult monkeys.

Far away from margay’s habitat, in North America, lives the Pink Lady’s Slipper, a plant that produces bright flowers that look ripe and juicy. Attracted by its appearance swarms of bees arrive to feed on its nectar. But there’s none! The Pink Lady’s Slipper tricks bees into carrying its pollen while providing nothing in return.

Such acts of deception – big and small – are common in the animal world. Evolutionary biologists believe deception was a smart mechanism that some species used to survive without having to fight with its enemies.

Why do we lie?

Primatologist Emil Wolfgang Menzel Jr. conducted a fascinating experiment in 1974 with a group of chimpanzees at a zoo. He chose one among the group (let us call him X) and showed him a hidden stash of food. The rest of the group was made to observe X from a distance.

Soon after, all chimps in the group started to follow X wherever he went. They seemed to know that X had some secret insider information. But here’s the interesting part - X also knew that his mates were suspicious. So he never publicly walked towards the food. Instead, he kept walking in circles or moving in the opposite direction. After a few days, the group became suspicious of X and started to observe him even more closely.

The experiment revealed that deception is a strategic mechanism that animals (and human beings) use to protect their own interest without having to engage in violence. The chimp X did not eat the hidden food in front of the group because he knew he could be overpowered by stronger members. Through deception, he avoided a conflict to protect his interest.

Menzel’s experiment heavily influenced the Social Intelligence Hypothesis or the Machiavellian intelligence hypothesis, which states that humans – and primates such as chimps – evolved large and complex brains not to solve “technical” problems such as finding food or making tools. It was actually to survive in large and complicated social groups. And surviving in a group without conflict, often, meant using trickery and deception.

When do we learn to lie?

Humans, obviously, are much more advanced than chimps when it comes to lying. Children need not be taught to lie. They learn it on their own, as part of their cognitive development. By the time a child is about 2-3 years of age, she knows that her knowledge of a certain event is different from the knowledge of others. Psychologists call it the theory of mind.

For instance, if a child secretly eats a cookie, to lie, she must understand that her knowledge of the event (eating the cookie) is different from that of her mother’s (who has not seen her eat it). Learning that difference and subsequently using it to their advantage (to lie) is, therefore, a normal part of a child’s brain development.

A Canadian study published in 2018 found that children who start lying early in their lives have better cognitive abilities than their peers. Which means, lying is like a workout for a young brain. If there are so many benefits to it, then why is lying considered wrong? Why do so many children’s stories end with a moral about being honest? To understand that, we must first learn about the different types of lies that we tell.

The types of lies we tell

Not all lies are the same, according to psychologists. They have categorised lies into three groups – prosocial, self-serving, and antisocial. Prosocial lies are the harmless ones that we say to flatter others and improve our relationship with them. They are what we call white lies, such as “your hair looks nice today” or “that shirt looks great on you”. We use these lies to make others feel good.

Self-serving lies are the ones we tell for personal gain or to escape punishment. For instance, lying to your teacher about being sick to do homework falls in this category. Antisocial lies are the ones said to cause intentional harm. This category includes the worst kinds of lies, such as hoax bomb threats, fake news, and spreading deliberate rumours within peer groups.

Why lying is a problem

Lying may be an evolutionary gift that human beings used to get their way without a conflict. But in a civilised society, lying does great harm. And that harm is both personal and social. At a personal level, the biggest casualty to lying is our mental health. Multiple studies have proven that persistent lying can cause significant mental stress and harm.

The stress is because to lie, we have to construct an alternate reality that will replace the true course of events. This alternate reality must be believable as well. Functional MRI studies have observed that when a person lies, neural activity peaks in the prefrontal cortex of their brain. This overload on the brain causes physical symptoms such as jitters, clammy hands, and rise in blood pressure. A polygraph, or what we call as lie detector test, actually works by measuring these physiological responses.

A study conducted in 2012 by professor Anita E. Kelly of University of Notre Dame, U.S., noted that people who stayed away from lying for about 10 weeks reported significantly better mental and physical health. On the other hand, another study done in 2016 found that repeated acts of dishonesty can affect our Amygdala - the region in our brain responsible for triggering emotional responses.

Which means, if we make lying a habit, the emotional responses associated with the act will gradually reduce. At some point, we will stop feeling guilty, ashamed, or embarrassed. And when the discomfort disappears, we gradually degrade from telling pro-social lies to antisocial ones.

Epistemic harm

What is the social impact of your lie? Philosophers say that when you lie, you inflict what is known as “epistemic harm.” Which means through your act of lying, you are damaging another individual’s ability to understand this world accurately and make informed decisions. It corrupts their perception of reality and could lead them to bad decisions based on false information.

Now, imagine if lying was normalised. There will be millions of people telling millions of lies to a million others. Nobody will be sure of what is real. There will be a thousand versions of “reality” and large groups of people will engage in bitter fights to prove their version is correct. Such conflicts will become irresolvable.

Just like how an economy depends on money for its transactions, a society depends on trust. Lying breaks that trust and makes social transactions impossible. We see that happening all around us. Trust deficit can make us haggle with auto drivers and hawkers over prices. It can make countries go to war with each other. It can make best of friends turn into bitter foes. Only truth can help rebuild trust. Which is why speaking and seeking the truth is not just a matter of personal ethics. It is a collective social responsibility.