It appears that watching TV, playing video games, and spending time on phones and tablets might lead to increased behavioral problems, at least in children 12 years old and younger. In a new study published in the journal JAMA Psychiatry, researchers at the University of Calgary performed a review of almost 90 scientific studies involving over 150,000 children. They found that a longer duration of screen time had a small but significant correlation with aggression, inattention, anxiety and depression in younger children.