What's the tradition behind hand holding during the Our Father at Mass?

In traveling around my diocese I've noticed that there are some parishes that are hand-holders and some parishes that are non-hand-holders and some people in the non-hand-holder parishes who persist in hand holding and some people in the hand holder parishes who abstain from hand holding. Also, there are some parishes where it is common to raise up your hands together for the doxology of the prayer. And some parishes where even unheld hands are held up like the priest does. I know that pure imitation of the priest isn't good (his hands are blessed, mine aren't), but what I don't know is if spontaneous hand holding by the congregation is totally licit and where the tradition came from. My mom told me it was, "something Protestants did in the 60's that Catholic's picked up on" is that all it is? Was there ever a Bishop who told his diocese to hold hands or not to hold hands?