I have to differ on your interpretation Essxjay of what a phrase like 'kiddo' means - americanism or not.

I do not recall a single occasion in which an American friend, colleage, customer or supplier, reservations agent, check-in clerk, ever called me 'kiddo'. Hence I think it is not normal parlance.

Kiddo - IMHO - is a form of paternalism - demeaning a person by referring to them like a child has to do with statements of power, issues of control and relationships based on weaker/stronger.

In what used to be a community - we now seem to have our first police. That I think is unfortunate.