The actor, who plays Lane Pryce in the AMC series, credited showrunner Matthew Weiner for writing silent scenes and subtle looks into his script.
"On another show, with different pressure from the studio, they'd want all that written in there," Harris told Radio Times. "They'd say there needs to be some lines in here to explain what isn't being said.
"Matt's position is, 'No, they wouldn't say anything because they're not that type of people'. That's why, I think, people find the show fascinating, because there's so much you read into it and all that stuff is there on purpose. He's totally aware of all of it."
Harris added that he believes Man Men's script to be an example of "adult" writing.
"I think on cable television the approach is that they're trying to attract an older audience, people who've seen it all before and want something else," he said. "And that's exciting for writers, too - they're being allowed to write for an adult audience."
Harris previously said that he enjoys the "challenge" of playing characters from the past.
Mad Men airs on Sundays on AMC in the US and Tuesdays on Sky Atlantic in the UK.
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