I started two eight year olds at about the same time last year - a girl and a boy. (I do have a lot of other pupils - these are just the ones I'm interested in!) I've been using Tricks to Tunes which doesn't introduce down and up bow symbols until the second book and have noticed that when they started using their bows, both initially started on up bows rather than down bows. The girl has now switched although I suspect that may be due to the fact that her mum used to play the violin and can guide her daughter a bit in these matters. The boy is still starting on up bows even though I have begun trying to get him to start with down bows. Interestingly, his bow hold is much better when he does start on an up bow, although that's obviously not good enough a reason to keep him doing it this way.
I was just curious what other people thought about this. I suppose to me the notion that you start on an down bow unless indicated otherwise is so deeply ingrained that it seems completely natural to me. It seems from these two and from another girl I taught briefly while filling in for another teacher that perhaps it is easier to start off with up bows. Is it better to have them bowing backwards to start with if it makes playing the violin easier for them? Is it going to cause problems later on if they get too used to doing it the 'wrong' way round?
Incidentally, while the series doesn't introduce the down/up bown symbols until the second book, I have been writing the symbols in myself so they will at least be familiar with them by the time they are introduced formally in the second book!