Many parents love to tell their children how special they are, but new research suggests this could cause them to live their lives as narcissists.

A team of researchers found children whose parents described them as "more special than other children" or claimed they "deserve something extra in life" were more likely to show signs of narcissism, Ohio State University reported.

"Children believe it when their parents tell them that they are more special than others. That may not be good for them or for society," said Brad Bushman, co-author of the study and professor of communication and psychology at Ohio State.

To make their findings the researchers surveyed parents and their children a total of four times over the course of one and a half years. They determined that while parents who overvalue their children usually have the best intentions, their actions could actually be a disservice to their children.

"Rather than raising self-esteem, overvaluing practices may inadvertently raise levels of narcissism," said lead author Eddie Brummelman, a postdoctoral researcher at the University of Amsterdam in the Netherlands.

The study included 565 children in the Netherlands who were between the ages of 7 and 11. Both children and parents included in the study reported how much emotional warmth was involved in the relationship, and children were assessed for levels of narcissism and self-esteem.

"People with high self-esteem think they're as good as others, whereas narcissists think they're better than others," Bushman said.

The team determined that while parental overvaluation tended to raise narcissism levels over time, it did not have much of an influence on self-esteem. Showing more emotional warmth as a parent did appear to help raise self-esteem in children.

The researchers noted parental overvaluation is usually not the sole cause of narcissism in children, which can also be linked to genetics and the children's temperamental traits.

"When I first started doing this research in the 1990s, I used to think my children should be treated like they were extra-special. I'm careful not to do that now," said Bushman, who is a father himself. "It is important to express warmth to your children because that may promote self-esteem, but overvaluing them may promote higher narcissism."

The findings were published in a recent edition of the journal the Proceedings of the National Academy of Sciences.