What makes us subconsciously mimic the accents of others in conversation

[ChazInAz]

7. Mea culpa!

It took a while to ditch my native Hungarian accent in exchange for my mother's Welsh one! (I have no idea how my parents met! They never talked about it.) Losing that took even longer. I grew up in an immigrant neighborhood consisting entirely of assorted Slavs and generic Bohunks, and mirrored everyone's accents. This did not help in sounding "American", and I always sounded vaguely foreign until getting into theatre. Lots of vocal training gave me the "Mid-Atlantic" accent that we know from 1940's cinema...vaguely British. Get me tired or angry, though, and I still sound like Bela Lugosi.
Even now, I bounce accents back at people. My late wife's Irish grandmother went to her grave convinced that I was a nice County Cork lad with a foreign name.