Size mattered most to iconic rebel McQueen says pal Robert Vaughn.

On the set of The Magnificent Seven competition was so fierce between stars Yul Brynner and McQueen that even the size of their horses mattered.

"Did you see the size of Yul's horse?" Vaughn recalled a highly agitated McQueen asking.
"I pointed out to Steve that my own horse, which was named Jumbo, was even bigger than Brynner's, but Steve was really angry," the former Man From UNCLE recalled.

Vaughn who also teamed with McQueen in The Towering Inferno revealed that Steve was so obsessed over rival Paul Newman that he made sure they both had exactly the same number of lines of dialog

"Steve never believed he was a good actor," Vaughn revealed. "Paul was a very articulate actor who wanted to talk through scenes, which was something Steve never did."

There's a word for it: insecurity.