As a devout follower of Full House growing up, I know that the girls didn't call Joey, "Uncle". However, people are being hardheaded and arguing with me that they did. Can anyone else help me prove/confirm this?

I've seen every episode atleast 5 times...the only references to Uncle Joey are when Danny, Jesse, or Becky is talking to Michelle or Nick/Alex when they are really young.

Jesse & Becky referred to him as Uncle Joey a few times in the series in front of Nicky and Alex as a sign of respect, probbly Becky decided it would be appropriate being from mroe conservative Nebraska.

However, the girls never call him that int he TV series, though in later books they do consistently, esp. Michelle.

Since Joey is in the basement apartment throughout in the books, there's less familiarity, but also the writers probably figure it's mroe logical that they be mroe polite and give himt hat title.

As for why "historically" in that universe, it goes back tot he idea of D.J. being much mroe proactive. In addition to nipping attitude and other behvior problems before they got too bad, & helping Michelle mature more quickly, D.J. likely decided when michelle was 2 or 3 that they should all start getting into that habit, just because it seemed the more polite thing to do. She, after all, was also maturing faster, as were her 2 younger sisters. Danny (and pam) had never minded them calling him Joey, but this was one way in the Book Universe for her to put her individual stamp on things.