Children's self-esteem generally goes down as TV watching goes up. But white boys are the exception, according to a new study published in the journal Communications Research.

Researchers from Indiana University surveyed close to 400 boys and girls between the ages  of 7 and 12, of whom 59 percent were black, and slightly less than half white, to see if there was a correlation between time spent in front of the TV and children's self-esteem. They tallied the amount of TV watched and had the participants complete an 11-item questionnaire intended  to measure overall feelings of self-worth.

The existing research on the impact of TV on children's health has focused on body image and eating disorders, Nicole Martins, an assistant professor of telecommunications at Indiana University and co-author of the study, told ABCNews.com. Given that children spend more than seven hours a day with some sort of media (computers, TV, video games), examining the influence of  media on how they feel about themselves seemed long overdue, she said.

The study authors said that while white male TV characters tend  to hold positions of power in prestigious occupations, have a lot of education and beautiful wives,  the TV roles of girls and women tend  to be less positive and more one-dimensional. Female characters are often sexualized, and success is often measured according to how they look.

Black men and boys are often criminalized on TV, the  researchers said, which can affect their feelings of self-worth.

According to the study, self-esteem has significant behavioral and emotional ramifications, and it is often correlated with motivation, persistence and academic achievement, particularly among children.

But Alan Kazdin, a professor of psychology and child psychiatry at Yale University, said self-esteem  had  not been found to  relate causally to anything at all. While it can be one measure of clinical depression, that does not mean it characterizes or causes depression.

"As citizens, we think of self-esteem as very important," said Kazdin. "But I deal with aggressive and violent children who have self-esteem that can be much higher than the average child. Yes, every parent wants their child to feel good about themselves, but high self-esteem is not an elixir to get you through life. It is not the protective factor we'd like it to be."

Building confidence in children, and helping them gain skills and competencies that contribute to a better life, such as learning instruments, playing sports or sticking with a difficult school lesson, will help do that. If children do not have friends, setting up "light play dates" will help build socialization skills, a "really important aspect of life," Kazdin said.

Martins suggested that parents limit TV time, and as Kazdin suggested, help their kids  gain skills that will improve  their lives.

"Too much time in front of the screen may displace real-life experiences, such as playing a musical instrument, playing ball in the backyard, that could build a child's feeling of self-worth," said Martins. "Another option would be to actively mediate   children's media use so that they can more easily understand fantasy from reality.

"Simple distinctions and conversations like this help mitigate the impact such an image might have on self-esteem and comparisons to media characters," she said.