Facebook just announced that it's pausing the rollout of Instagram Kids, a version of the platform for children under 13 years old, while it works to "demonstrate the value and need for this product.” The pause comes after a Wall Street Journal story a couple of weeks ago about the company's research on how Instagram affects teens. One finding? A third of teen girls who have body image issues say Instagram makes them worse. Marketplace's Marielle Segarra speaks with Jean Twenge, author of the book “iGen: Why Today’s Super-Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy — and Completely Unprepared for Adulthood.” She said the effects could be even worse for younger kids.