Bazinga! 'Young Sheldon' gets his own 'Big Bang Theory' spinoff

What was "The Big Bang Theory's" Sheldon Cooper like as a child?

The prequel series "Young Sheldon" sets out to answer that question. Debuting Monday, Sept. 25 - right after the 11th-season premiere of the parent show, and before it starts its regular Thursday run in November - the CBS comedy introduces Iain Armitage as the younger incarnation of the brainy, fussy Sheldon, who's way wiser than his years. The show also retains the voice of "Big Bang" Emmy winner Jim Parsons in the title role: An executive producer of "Young Sheldon," he also narrates it.

"When we shot the pilot," Parsons recalls, "I was able to interact with Iain a lot, and kind of discuss certain things that are peculiar to this character."

Seen as Shailene Woodley's son in HBO's "Big Little Lies," Armitage auditioned to become "Young Sheldon" by recording an iPhone video last Christmas at his grandmother's house in Georgia.

"My mom was actually holding the phone," he reports, and the result won over the show's makers. Executive producer Chuck Lorre remembers Parsons' initial reaction being, "I think we just got extremely lucky," though Armitage hadn't seen much of "The Big Bang Theory." The 9-year-old actor reasons, "It is aimed at a different audience than me. Also, I don't watch a lot of TV, but I saw a couple of appropriate clips."

Annie Potts will play Sheldon's grandmother, or "Meemaw," and another intriguing piece of "Young Sheldon" casting is that of the character's mother. Laurie Metcalf has appeared as Mary Cooper on "The Big Bang Theory." On the spinoff, the role is assumed by Metcalf's own daughter, Zoe Perry (who has acted opposite her father, Jeff Perry, on ABC's "Scandal").

"Genetics do a lot for me," Perry says of following her mother. "Certain mannerisms just come with the territory. ... I think what's so wonderful and a privilege to play Mary Cooper at this age is that we don't know her at that stage of her life yet, so I think it provides me a little bit of flexibility."

"Young Sheldon" is the first of Lorre's shows not to be filmed in front of a studio audience.

"It's more intimate," the producer notes. "The pacing, obviously, is very different. The actors aren't having to 'hold' for laughs; they're not playing to the proscenium. Also, we knew going in that we were going to be working with a cast of young children, and it seemed like the more appropriate way for them to get the best work - in a closed setting where they had the time to develop these characters."