Los Angeles Times: The kids already know Snapchat. Young adults, too: Six in 10 people ages 13 to 35 in the U.S. use Snapchat. It’s nowhere close to popular among the over-35 crowd. But there are signs that’s changing. The raw numbers are small so far, but Snapchat use among older adults is growing fast. The growth is led by parents and siblings looking to stay in touch with younger family members, experts. said.