Your first paragraph: Exactly!
Although I would not say my husband is speaking slowly, it's more that he's more detailed than I am. He also calls me out on hyperbole a lot, which I am very glad he does, because I do that a lot too.
Yes, I think "among friends" or any other people who are close is often the driving factor in such overlapping. I hadn't really thought of any regional or gender or even family size variables. So all of these comments have been fascinating. It's amazing what all goes into making a person and a personality and a communication style.
Thanks for reading!