I'm pretty new to this board, but I've been doing aikido sinc 1975 and lived in Japan in the early 1990s. Aikido Journal recently published my essay on their blog:
Basically, my idea is that some very highly-skilled master noticed children's ways of escaping their handlers when they didn't want to be picked up. The master used this type of movement, added appropriate locks and aiki-jujutsu was born.
Any thoughts on this?