Re: HOW does aikido change us?
I also think that aikido has changed me over the years, and almost every other aikidoka I've spoken to has said the same thing - a good basis for generalization to me. Fair enough, short of a twin-study it's hard to prove scientifically, but there would seem to be at least some truth in the matter.
To tackle the debate from a different angle, what feature does aikido have that would lead one to believe it will change the practitioner more than many other activities? or to suggest it could make a more effective vehicle than other things? I would suggest:
1. It is a good exercise and many studies how that exercise is a significant factor for mental health.
2. It involves social and touch elements.
3. From a physiological point of view, it brings up Freudian, Jungian and Adlerian themes -eg power and vulnerability, father figures, archetypes, etc.
4. The reciprocal, non competitive nature of the uke-nage relationship - CRUCIAL.
5. It deliberately trains posture, movement and breath.
6. The emphasis on manner and etiquette.
7. It exposes practitioners to related healthy philosophies and practices such as Buddhism, meditation, etc.
8. It contains an intensity, and an existential, life and death element.
9. In order to do it you have to be relaxed.
Re horse riding, I think this activity also contains many beneficial elements. I have some experience in outdoor education, which has developed into a kind of "Western Budo" where by children are developed through psychologically intense (eg climbing), or team work activities. So sure, aikido isn't the only way.
Genuine question: How fair would it be to say that the purpose of Budo is some kind of personal change?