Many parents make it clear that honesty is good while lying is bad, and yet an adult's responses to their kid's lies aren't always consistent.

New experiments emphasize this hypocrisy by showing parents can be more judgmental of overtly honest, harshly expressed truth-tellers, than polite, subtle liars.

The authors think children can sense the discrepancy. Most kids aren't explicitly taught to lie, but the reactions of their parents might teach them that bending the truth is less risky than the alternative.

That's not necessarily a bad thing. Virtually everyone learns to twist the truth to preserve another person's feelings, for example. Lying is an important step in a child's emotional and social development, indicating a theory of mind, or the ability to understand that other people have different thoughts, desires, or needs.

When a lie is made for self-serving reasons, experiments suggest it is often judged harshly by parents.

The new experiments are the first to explore what feedback children receive from their parents when they tell a blunt truth (as in "I think your hat is ugly"), as opposed to a more subtle, polite lie (as in "I think the color of your hat is nice").

The study was conducted among 142 parents, who watched a series of eight videos depicting a child actor in various scenarios. While observing the footage, participants were asked to imagine the kid was their own and think about how they might react to their behavior.

In one filmed scenario, for instance, a child was asked by a parent to reveal the location of a sibling, one who happened to also be in trouble with the parents.

In the blunt truth-telling video, the kid responded, "She's under the porch." The blunt liar, meanwhile, replied, "She went to the library."

The subtle liar said, "I think she might have gone to bed or something." And the subtle truthteller answered, "I think she might be outside."

In another filmed scenario, the child lied not to protect a sibling but to be polite.

After each video, parents rated the child on characteristics such as trustworthiness, kindness, good behavior, competency, likeability, friendliness, intelligence, honesty, and warmth. They also gave points for how good a person they thought the kid was.

Generally, lying was viewed more negatively by adult participants than honesty, but there were exceptions.

When lying to be polite, a kid was viewed more positively by adults, and they were more likely to be rewarded than even the most polite truthtellers.

When a child was lying to protect a sibling, however, they were judged more harshly than truthful 'tattletalers'.

This form of honesty doesn't exactly endear a parent to a child. Ratings of likeability tend to drop when a kid tells on their sibling, adding weight to the old adage that 'no one likes a tattletale'.

At the same time, however, tattletales in experiments were considered more trustworthy by adults.

"Thus, although cultural mores dictate that lying is a negative behavior, a much more nuanced message is likely communicated to children engaging in prosocial lie-telling," the authors write.

"While brutal honesty might elicit dislike, it may also engender a perception that the individual can be trusted – that one offering such a blunt assessment must be honest."

Future research will need to examine the child's perspective in similar scenarios to see if the authors are right in assuming how kids interpret and learn from their parent's reactions.

The study was published in the Journal of Moral Education.