Yep, genetics certainly can be indubitable. :-)
I have a grandson that I did not get to know as he was growing up. (long story) We are all getting to know him now. He’s 21. My son, his Dad, had a party at his house and his son was talking about where he lives. He said that there was nothing to do but go to parties and become inebriated. Someone poked fun at him for it, “Why not just say “drunk”?!” We all jumped on them and stated that the whole family speaks that way. Guess it really IS genetics!