A new study has found that when children are praised for being smart, not only are they quicker to give up in the face of obstacles, but they are also more likely to be dishonest and cheat.

The international team of researchers found that kids as young as three behave differently after being told either 'you are so smart' or 'you did very well this time'.

The new research builds on well-known work by Stanford's Carol Dweck, who has shown that praising a child's innate ability instead of their effort, or a specific behaviour, has the unintended consequence of reducing their motivation to learn and their capacity to deal with setbacks.

The new study, published in the journal Psychological Science, demonstrates that this affects children younger than previously thought and that there is also a moral dimension to different kinds of praise.

"It's common and natural to tell children how smart they are," said co-author Gail Heyman, from the University of California San Diego. "Even when parents and educators know that it harms kids' achievement motivation, it's still easy to do. What our study shows is that the harm can go beyond motivation and extend to the moral domain. It makes a child more willing to cheat in order to do well."

For the experiment, the team asked 300 children from eastern China to play a guessing game using numbered cards. Half of the children were three-year-olds while the other half were aged fove. The researchers praised the children either for being smart or for their performance, while a control did not receive any praise at all.

After praising the children and making them promise not to cheat, the researchers left the room in the middle of a game while continuing to monitor the kids using hidden cameras to check who took a sneaky peek at the numbers on the cards.

The results of the test suggested that the children who were praised for being smart were more likely to act dishonestly than those were praised for their performance or who got no praise at all. There were no differences between boys and girls.

Another recent study conducted by the same authors, published in the journal Developmental Science, showed that the consequences are similar even when children are not directly praised for being clever but are simply told they have a reputation for being smart.

The researchers think this is because praising ability is linked to performance pressure in a way that praising behaviour isn't. So, when children are praised for being smart or told they have a reputation for it "they feel pressure to perform well in order to live up to others' expectations, even if they need to cheat to do so", according to Li Zhao, co-author of the study.

"We want to encourage children. We want them to feel good about themselves", said Kang Lee, another co-author of the latest study. "But these studies show we must learn to give children the right kinds of praise, such as praising specific behaviour. Only in this way will praise have the intended positive outcomes."