It’s actually a big developmental milestone. BlurryMe/Shutterstock.com
For the liar, telling a lie has obvious costs. Keeping track of the lies one tells and trying to maintain the plausibility of a fictional narrative as real-world events intrude is mentally taxing. The fear of getting caught is a constant source of anxiety, and when it happens, the damage to one’s reputation can be lasting. For the people who are lied to the costs of lying are also clear: Lies undermine relationships, organizations and institutions.
However, the ability to lie and engage in other forms of deception is also a source of great social power, as it allows people to shape interactions in ways that serve their interests: They can evade responsibility for their misdeeds, take credit for accomplishments that are not really theirs, and rally friends and allies to the cause. As such, it’s an important step in a child’s development and there are cognitive building blocks that must be in place in order to successfully lie.
One way research psychologists have sought to understand the reasoning behind the choice to lie versus tell the truth is to go back to when we first learn this skill in childhood. In some studies, researchers ask children to play a game in which they can obtain a material reward by lying. In other studies children are faced with social situations in which the more polite course of action involves lying instead of telling the truth. For example, an experimenter will offer an undesirable gift such as a bar of soap and ask the child whether he or she likes it. Yet another method is to ask parents to keep a written record of the lies that their children tell.