Can confirm that this was standard practice in the 1980s - We'd go to TG&Y and be told to check in at the front at a certain time - usually an hour or so after we entered. Sometimes, we'd get a bit of money to buy popcorn. Did a fair amount of wandering about unsupervised in the mall, too. It as a kind of adventure - a parent or parents were there - but not hovering around us. I usually just ended up in a book store or in the book section at Target/TG&Y (yes, they had tons of books) - I don't recall feeling any fear - just wonder.