Watch a Preview of “Who Do You Think You Are?” on TLC

By Diane Haddad

Excited for the fourth season of “Who Do You Think You Are?” premiering July 23 on TLC? Here’s a video preview.

It’s longer than the teaser that was released at the end of June, and drops clues to the family history surprises in store for some of the celebrity guests. You’ll see them in the video: Kelly Clarkson, Zooey Deschanel, Chris O’Donnell, Christina Applegate, Jim Parsons, Cindy Crawford, Trisha Yearwood and Chelsea Handler. (We posted here about who these people are.)