The absolute truth?
Lying to an employee is bad. Lying to the public is even worse. But according to new research, children believe that telling a lie that upsets a classmate is absolutely fine, as long as your friends still like you afterwards.
Minghui Gao, of Arkansas State University, collated and studied 30 years of research into primary and secondary pupils' attitudes towards lying.
She found that children as young as four judged lie-telling on a sliding scale of moral relativity. The more selfish the lie, the more reprehensible it was.
Certain types of lies were deemed categorically unacceptable. For example, pupils believed that those that caused trouble or cost the victim money were never tolerable.
Similarly, lies told by authority figures were particularly objectionable. A lie told by an employer was judged to be more damaging than one by an employee. And a lie told by a politician was the worst of all.
Dr Gao said: "Children's moral judgment of lies told by adults was affected by the status differentials of the liars . A lie told by a person with an occupation affecting many people was more reprehensible than a lie by a person in an occupation affecting fewer people."
Lies were deemed less reprehensible when they were intended to save others from shame, or protect them from punishment.
But motivation was not always the biggest concern. In fact, even the most selfishly harmful lies would be willingly overlooked, if they helped to strengthen bonds with classmates.
Attitudes also changed with age. Primary pupils tended to disapprove of both anti-social and white lies, while teenagers readily accepted the need for the occasional tactical untruth.
Ninety-two per cent of five-year-olds interviewed in one study said that it was always wrong to lie, whatever the context. By the age of 11, this figure had dropped to 28 per cent. And by the age of 15, only five per cent held such clear-cut views.
Similarly, attitudes varied according to sex. A study of 2,500 pupils revealed that boys tended to approach moral issues with a black-and-white emphasis on justice and rules. Girls, by contrast, were more concerned with relationships and responsibility to others. Despite - or because of - this, boys were generally more tolerant of lie-telling.
The sex of the victim also affected how the lie was perceived. Prefiguring adult relationships, girls believed that lying to a boy was generally acceptable. By contrast, a lie told by a male to a female was never all right.
Boys disagreed. They thought that lying to a girl was entirely acceptable, while a girl who lied to a boy had committed an unforgivable crime.
Dr Gao believes that an awareness of children's relationship to truth could help teachers understand pupils' motivations in the classroom.
"People judge and evaluate their own actions, not only from the wellbeing of the recipient of the actions, but also from their own wellbeing, self- interest, consequences and emotional experiences," she said.
"More research is needed on whether and how children's moral judgment of lying might be related to . actual lie-telling."
Elements affecting children's moral judgment of lying, by Minghui Gao; email@example.com.