It really is the very rare bird who will allow a stranger to touch. Clyde is very tame and takes immediately to a person here and there, but for the most part, if he doesn't know you, he doesn't WANT to know you. I have a friend who has a T-shirt with very rude language that I won't repeat, but the essence of the message is "go away, I have enough friends"

. That shirt could have been designed by Clyde.
Jade bites US if we get too familiar, so she most emphatically will bite other people if they get too friendly. We had an incident recently with my brother-in-law, whom Clyde adores, but Jade does not remember him -- he lives out of state and visits a few times a year. When he approached Jade and we both warned him that she would bite him (and she warned him, too), yet he insisted on poking his hand at her and, yup, she bit him, it served him right.
I visited some people who have several large birds (macaws and cockatoos, an eclectus) and the man told me I could pet one of the macaws who he takes to visit schools and hospitals, even though that bird's body language clearly told me I COULD pet her, I was still a little hesitant. I wouldn't have dreamed of trying to pet any of the others; they didn't know me and didn't want to, though they were quite willing to talk to me from a distance.