In reply to Rob Laird:
Just a couple of observations on what kids will trust, based on my own kids, in case it's of interest.
My 7 year old is happy to climb on the auto belay working higher up and jumping off each time. He is much more reticent to be belayed by a human being. In his own words, "I trust the auto-belay more than the daddy-belay". I'd say he's not that confident in the auto-belay either, compared to other kids his age.
Back out in the outside world, going bouldering sees both my kids climbing freely, having a lot of fun. In this case, they develop their own skills and build self-confidence. For safety, I am there is spot them. It seems that taking the kids bouldering is a much more rounded, fulfilling experience for the kids... even if it's harder work for me keeping them safe.
If I had a point - it's that my son seems to trust his own ability more than ropes or equipment which are not under his control.
Post edited at 23:18