In a March 2017 study published in Physchological Science, researchers studied 300 Chinese preschoolers. Half of those 300 were 3-year-olds and the other half were 5-year-olds. They were split into three different groups: one group was praised for its ability ("You are so smart"), one group was praised for its performance ("You did very well this time"), and one group was given no praise.
The children took part in a guessing game that involved a child choosing whether a hidden card in the researcher's hand had a number printed on it that was more or less than six. Children who were praised for their smartness (the ability group), regardless of age, were more likely to cheat and peek at the card when the researchers left the room, even after the researcher had asked the child to promise that he or she would not peek.
Researchers say the reason for cheating might be linked to pressure. If you're constantly praising your child for being smart, he or she might become scared of disappointing or upsetting you, study researcher Kang Lee told Canada's CTV News. Children will then cheat so they don't fail your expectations, he said.
“It’s common and natural to tell children how smart they are,” co-author of the study and development psychologist Gail Heyman said in a UC San Diego press release. “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.”
This research strengthens the case for psychologist Carol Dweck's decades-long research, which says that children should be praised for their efforts rather than their abilities because it increases a child's motivation. Dweck advocates for constructive criticism — "Spelling isn't your best subject" versus "spelling isn't your best subject yet." — because it fosters a "growth mindset."