Thanks guys. A lot of people say that we look really similar and I think sometimes it's more in certain pictures than in person. But we sound almost identical, especially if we have been around each other a lot. We've confused our own mother, spouses, and I think even my sister's dog by sounding so similar.
I don't really look much at all like any of my siblings. We actually all look really different! But like you, my sisters and I sound exactly alike, and our mom too, so the four of us never know which one we're talking to and confuse other people all the time on the phone.
Similar situation with me, my brother and father, and my uncle and cousin on the same side of the family. Expect that we
can/could tell each other apart, but no one else seems/seemed to be able to.*
And yeah, it's a combination of nature and nurture. There's a "dial" we can "turn up" to really milk it.
* - Past tense only because my uncle has passed away.