Zimmerman and Christakis1 reported that early television exposure in children younger than 3 years was associated with deleterious effects on cognitive development, such as reading recognition at age 7 years. Their findings were based on a longitudinal study and supported the American Academy of Pediatrics' guidelines that parents should discourage television viewing for children younger than 2 years.2 Our previous survey on development and rearing of 18-month-old children (n = 1900) in 3 areas of Japan also suggested that children with frequent television viewing (>4 hours per day) would have delayed development of meaningful word speech, even with parental talking during television watching. Because of these findings, the Japan Pediatric Society proposed that children younger than 2 years of age should avoid frequent television viewing.3 To clarify the reason for the statistical association between delayed development in speaking and heavy television viewing, we conducted an observational study.