University of Iowa researchers examined the impact of television and parenting on children's social and emotional development.
They found that background television - when the TV is on in a room where a child is doing something other than watching - can divert a child's attention from play and learning.
It also found that non-educational programmes can negatively affect children's cognitive development.
"Kids are going to learn from whatever you put in front of them," said Deborah Linebarger, associate professor in education at the UI and the lead author on the study.
"So what kinds of messages, what kinds of things do you want them to learn That would be the kinds of media you'd purposefully expose them to," said Linebarger.
The findings come from a national survey of more than 1,150 families with children between 2 and 8 years old.
Linebarger and her team looked at family demographics, parenting styles, media use, and how those factors could impact kids' future success.
The team found a relationship between the content children are exposed to and their executive function, an important facet in learning and development.
This was especially true among children in families she identified as "high risk" - in families living in poverty or families whose parents have little education, for example.
Yet even kids in high-risk families who watched educational television saw increases in executive function, the researchers found.
Regardless of family demographics, parenting can act as a buffer against the impacts of background TV, researchers found.
The study was published in the Journal of Developmental & Behavioural Pediatrics.