On CBS' new drama Bull, the titular character played by Michael Weatherly is allegedly modeled on Dr. Phil McGraw and his professional beginnings as a trial scientist - a.k.a. a person who analyzes juries to see which way they're leaning.

But how much is Weatherly's character really based on Dr. Phil? Turns out, not very much. (For starters, Dr. Jason Bull doesn't have a Southern accent.) But that's not to say McGraw hasn't had an integral role in the show.

"He was there every day of the pilot," star Chris Jackson, who plays Bull's colleague Chunk, tells TVGuide.com. "We had an opportunity to sit with him and meet with him for several hours before we started to shoot, just to get a sense of what his role was, what the company was really about, and as the real-life iteration of Bull, what his team meant to him."

Bull: What did we learn about Jason Bull?

In watching the show, it becomes clear that Bull was inspired more by the world McGraw inhabited and the field of trial science rather than by the man himself.

"He was a big factor in creating that world," adds Annabelle Attanasio, the daughter of Bull creator Paul Attanasio, who also stars in the show. "So learning it firsthand and hearing real stories from him has helped us so much in understanding how the world works."

That's not to say, though, that Weatherly isn't drawing upon McGraw's influence.

"It's almost astonishing how well he reads people," the NCIS alum says. "It's intimidating to sit and talk with Phil McGraw, because he understands and gets things. ... He says he used to be able to, [based on] how somebody walked in and sat down, he would be able to decide whether or not that person was going to be good for their client."

See what else the stars of Bull had to say about Dr. Phil's role in the show in the video above.

Bull airs Tuesdays at 9/8c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)