Three decades ago, there were two big events at my house. My twins, Jonathon and Hillary, were born on March 31, joining their 3-year-old sister, Amanda. And, 4 1/2 months later, “Rugrats” premiered.

“Arthur” and “Barney” are OK for toddler TV-watching. But not “Rugrats” and certainly not “Power Rangers,” reports a new study of early TV-watching and future attention problems. The research involved ...