(CNN) -- We've heard it all: from the correlation between TV viewing and childhood obesity to the idea that excessive TV viewing can negatively affect children's grades.
But according to a new study, watching TV might actually boost your child's self-esteem -- that is, if he's a white male.
Parents of white girls and African-American children, however, might want to limit the amount of time their kids spend in front of the tube. The self-esteem of white girls, black girls and black boys decreases with TV consumption, says the study, published in Communication Research.
Over the course of one year, Kristen Harrison and Nicole Martins surveyed about 400 black and white Illinois students. All of the 7- to 12-year-olds are from lower-middle to upper-middle socioeconomic communities, said Harrison, a professor of communication studies at the University of Michigan. Black children surveyed, on average, spent an extra 10 hours watching TV each week.
With the definition of self-esteem being an overall feeling of self-worth, Harrison told CNN, kids were asked reverse-coded questions such as, "Are there a lot of things about yourself you would like to change?"
While the study focused solely on how the amount of time spent in front of the TV affects a child's self-esteem, the programs likely are what give white boys a confidence boost, said Amy Jordan, director of the Media and the Developing Child sector of the Annenberg Public Policy Center of the University of Pennsylvania.
Boys making the transition from elementary to middle school are probably exposed to superhero cartoons, Jordan said, adding, " 'Superman,' 'Batman,' X-Men.' The lead characters of these shows tend to be male."
But Jordan added, "In recent years, creators of children's programming have worked hard to improve diversity and include strong female characters."
For white boys, "regardless of what show you're watching ... things in life are pretty good for you," Martins, an assistant professor of telecommunications at Indiana University Bloomington, said in a statement. "(White males) tend to be in positions of power; you have prestigious occupations, high education, glamorous houses, a beautiful wife, with very little portrayals of how hard you worked to get there."
A similar 2010 study, which didn't put an emphasis on the race and gender of its participants, found that prolonged TV exposure could cause a child to perform poorly in the classroom, be victimized by classmates and increase body mass index. The study, conducted by Linda Pagani, a professor in the School of Psychoeducation at the University of Montreal in Quebec, followed more than 1,300 children from the time they were 29 months old.
And in 2009, Nielsen reported that TV viewing among kids was at an eight-year high, with 2- through 11-year-olds watching between 22 and 24 hours of TV each week. That's in addition to the amount of time they spent watching shows and movies on DVR, DVD, VCR and game consoles.
So while it's likely best for parents, regardless of their child's race or gender, to keep a mindful eye on TV consumption, Harrison and Martins' research suggests it's especially important for parents of girls and African-American boys.
Kids are impressionable, said Michael Brody, chair of the media committee of the American Academy of Child and Adolescent Psychiatry. It affects them when they don't see themselves represented on TV, and it affects them when the young people who look like them are seen doing something wrong, he added.
"Just like, most of the time on TV when somebody is mentally ill, it's usually a young woman," Brody said. "In terms of my own profession, whenever there's a psychiatrist on a program he's usually some maniac. ... That affects my self-esteem."
To that end, Harrison suggests that parents make sure their kids "spend time cultivating the relationships and skills that make you feel like a valued person."
Harrison, whose 6-year-old daughter is only permitted to watch TV at home on Friday nights, said the rules would be the same regardless of the sex of her child. Despite the self-esteem boost reported for white boys, she added, there are too many other negatives associated with watching a lot of TV.