Department of Maternal and Child Health, National Research Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan.
Our previous population survey of 18-month-old children suggested an association between delayed language development and heavy TV viewing. We therefore collected all 85 videos described as children's favorites in that questionnaire to examine relationships between the characteristics of habitually viewed videos and language development. In the language delayed group, compared to the non-delayed group, the types of videos preferred more were "realistic animations" and "baby education" and the characteristics of videos were contained few close-ups of characters facing viewers, continued uninterruptedly between stories, had constant movement or transformation of characters, had a high frame rate of animation, and that adults readily kept on watching the videos even with the sound off. These characteristics were seen more in videos the above two types. These findings imply that habitual television/video viewing with characteristics that are not apt to elicit parent-child communication for long hours may affect delayed language development in young children.