Both the quantity and the content of television viewing by children may affect social behaviors long term, with effects that may last into adulthood, the results of two studies have shown.
In one randomized, controlled trial involving 565 preschool-aged children in the United States, coaching parents to reduce viewing of violence on the screen and to increase exposure to prosocial programming resulted in significantly less aggression and more prosocial behavior in the children after 6 months compared with the control group, effects that mostly were maintained at 12 months, Dr. Dmitri A. Christakis and his associates reported.
A separate longitudinal study from New Zealand followed 1,037 people from birth to age 26 years and found a significantly increased risk for antisocial outcomes in adults who had watched the most TV as children. Every extra hour of weeknight TV watching as children was associated with a 30% increase in the likelihood of having a criminal conviction by age 26, reported Lindsay A. Robertson and her associates.
Previous studies have shown that children imitate what they see on the screen and that reducing TV watching reduced aggression in 9-year-olds. Few studies have looked at preschoolers or at interventions aimed at content, Dr. Christakis said.
His study found that children fed a "media diet" deemphasizing violent programs and promoting viewing of programs that focus on sharing, caring, and education had Social Competence and Behavior Evaluation (SCBE) scores at 6 months that were 2 points better than in the control group, a significant difference that continued at 12 months (Pediatrics 2013;131:431-8).
The study did not try to change the amount of screen viewing, and both groups increased TV watching during the study, which often happens as children grow older. The likelihood of adults watching TV with their children did not differ between groups and remained stable throughout the study, despite efforts to promote coviewing, said Dr. Christakis, director of the center for child health, behavior, and development at Seattle Children’s Hospital and professor of pediatrics at the University of Washington, Seattle. He also is on the American Academy of Pediatrics’ executive committee on children and media.
"The central point is to not just talk about turning off the TV. It’s about changing the channel. The message to turn off the TV, frankly, falls on deaf ears," he said in an interview.
He likened the intervention to harm reduction, such as programs that distribute clean hypodermic needles to injection drug users in order to reduce the transmission of HIV.
The study randomized 820 children aged 3-5 years who were recruited from community pediatric practices and analyzed outcomes data on 276 in the intervention group and 289 in the control group. One of three case managers worked with parents in the intervention group to discuss the child’s media use and set goals (involving anything with a screen – TVs, DVDs, videos, and computers, for example). Every month for a year, the parents received phone calls for coaching, mailings of customized TV program guides geared toward the family’s available channels with recommended programs, a newsletter with tips and reinforcing messages, and in the first 6 months, DVDs with preview clips of suggested programs to pique the children’s interest.
The control group received the same number and amount of contacts, but these focused on nutrition, not screen viewing.
The effect sizes of the intervention were small but comparable to results of other studies that tried to change parenting practices or directly change children’s behaviors, he said. Subgroup analyses suggested that the media-diet intervention may have improved behavior scores in low-income boys more than in others.
Steering parents toward good media content is "something that pediatricians can do," perhaps with the help of resources like the reviews on CommonSenseMedia.org, Dr. Christakis suggested.
The New Zealand study followed a cohort of children born in 1972-1973, and compared child assessments at ages 3, 5, 7, 9, 11, 13, 15, 18, 21, and 26 years with government data on criminal convictions through age 26 (Pediatrics 2013;131:439-46).
Those who watched more weekday television between ages 5 and 15 years were more likely to be among the 60 adults diagnosed with antisocial personality disorder at age 21 or 26, reported Ms. Robertson of the University of Otago (New Zealand). Among those who watched more than 3 hours per day, approximately 16% developed antisocial personality disorder, compared with approximately 9% of those who watched less than 2 hours per day.
Males were more likely than females to have a criminal conviction, but increased screen viewing raised the risk of conviction in both sexes. Approximately 35% of males and 12% of females who watched more than 3 hours per day ended up with criminal convictions, compared with approximately 19% of males and 3% of females who watched less than 2 hours per day.