A recent Canadian study has warned that early exposure to television is detrimental to children's health, academic achievement and social development.
Researchers found that every additional hour spent watching television at 29 months, beyond US recommended guidelines, corresponded to small decreases in classroom engagement, math achievements, and time spent on physical activity in later years.
As well, it lead to increases in victimization by classmates, higher consumption of soft drinks and snacks, and more body fat by the time children reached the age of 10, according to the study.
"Common sense would suggest that television exposure replaces time that could be spent engaging in other developmentally enriching activities and tasks that foster cognitive, behavioral and motor development," the researchers said.
Past studies of adolescents' television viewing habits found this to be true. This study is the first to look at how television affects much younger children.
"Broadcasting has an educational orientation when targeting preschoolers, which might have some cognitive benefits," the researchers opined.
"Nevertheless, preschool televiewing remains a cognitively passive activity at a time when key experiences for developing attention and behavioral self-regulation are expected to occur."
Children in this "critical period," for example, learn how to process information, interact with their environment and eventually use logic to understand math and science.
Television watching had no impact on reading skills, the study noted.
The researchers asked parents to note their children's viewing habits at 29 months and 53 months of age. At 10 years, parents and teachers then reported on the 1,314 children's academic abilities, health and well-being.
The American Academy of Pediatrics discourages any television exposure during infancy and less than two hours per day beyond two years of age.
Children in the study at 29 months watched an average of 8.82 hours of television per week, rising to 14.85 hours by 53 months.
The study led by Montreal University's Linda Pagani was published in the current issue of the American Medical Association's Archives of Pediatrics and Adolescent Medicine.