I grew up with backless stools at the breakfast bar. I do remember sitting on a stool with a back when I was really young, but I think that had more to do with there only being space for four stools (two on each side), and when we ate there as a family they pulled up the step stool/seat thing for me, since I was the smallest and could fit on the end. I remember sitting at the bar and having lunch sitting on the backless stools when I was around four. It seems like a pretty good age to handle it and be safe, as long as the stools are stable...some tip too easily to make it easy for little kids. Ours were kind of tippy, and I do remember a couple of spills, but it didn't kill me.