lying: kids vs. adults

From Shirley Wang in the WSJ...

Your child tells you he didn't eat a cookie despite the tell-tale crumbs all over his mouth. You call your boss to say you're taking "a sick day," feigning a cough while on the phone. You're both lying, but is it the same?

Whether we're 2 years old or 62, our reasons for lying are mostly the same: to get out of trouble, for personal gain and to make ourselves look better in the eyes of others. But a growing body of research is raising questions about how a child's lie is different from an adult's lie, and how the way we deceive changes as we grow....One intriguing new study suggests that lying may spring from a completely different part of the brain in children compared with adults....lying is a sign of normal maturation.

Dr. Lee and Victoria Talwar, a colleague he often collaborates with at McGill University, conducted a series of studies in which they bring children into a lab with hidden cameras. Children and young adults age 2 to 17 are enticed to lie by being told not to peek at a toy—often a plush purple Barney dinosaur—that is put behind the child's back. The test giver then leaves the room for one minute, ostensibly to answer a phone call, giving the child ample time to peek at the toy. Whether or not the child sneaks a look is caught on tape.

For young kids, the temptation to cheat is "tremendous" and 90% peek in these experiments. Even adolescents and adults are tempted in similar situations, says Dr. Lee. When the test giver returns to the room, the child is asked if he or she peeked. At age 2, about a quarter of children will lie and say they didn't. By 3, half of kids will lie, and by 4, that figure is 90%, studies show.

This trend continues until kids are about 15. By that age, nearly everyone who cheated in the experiment will lie about it. The good news: The number of liars begins to decline beyond this age. By 17, the percentage that lies drops to about 70%.

Researchers have also examined why some kids lie more than others, and have found that it isn't related to better moral values or religious upbringing. Rather, it's kids with better cognitive abilities who lie more. That's because to lie you also have to keep the truth in mind, which involves multiple brain processes...

As the children and adults lied, the researchers expected to see increased blood flow due to neural activity in the frontal regions of the brain, where executive functioning is thought to be carried out. That happened in adult scans, but none of the frontal regions in the children's brains showed the activity....