I was specifically wondering what led Stefan to come to his conclusion.So, the question is still open to Stefan..... Thanks.
So, I have to reply
I was a bit confused by your question, the first time you asked it on this thread. Others have agreed that there is a tendency for kids to quit when they reach puberty, so I thought that this was common knowledge.
If you have found a way to keep your kids through that transition - congratulations! Please, continue to share your experiences, since you are surely on to something.
Me, I have direct and indirect experiences of kids tending to leave when they become teens. In Sweden, aikido belongs to the Swedish Budo & Martial Arts Federation, of which I am a board member, and I have talked to representatives of most of these arts, and they all have the same experience regarding kids turning into teens.
That is why I started to speculate that it has to do with the need in kids to change their lives almost completely, in their passage from children to adolescents.
Does that answer your question?