It’s a term coined by the late Dr. Albert Ellis. To me, it’s means choosing to see whatever others think, feel, say or do as being understandable given what their life experiences have been. That doesn’t mean we have to like, agree with or tolerate what they do. There are a lot of things others think, feel, say and do I don’t agree with. I'm hearing a lot of it from neo-Nazis and white supremists lately. However, I strongly suspect that if any of us had walked a mile in their shoes, grown up in the environments they did, had the life experiences they did, we might very well have turned out the same way.
I like to use a formula to explain: NATURE + NURTURE = PERSONALITY. Where NATURE is all those constants about human development and psychology, NURTURE is a person’s life experiences, and PERSONALITY is their pattern of thoughts, feelings and behaviors. It’s like a + b = c, where a is a constant, and b is a variable. If a stays the same, and you change b, c changes. Likewise, a person’s PERSONALITY is greatly influenced by their life experiences.
The opposite of UOA is what Dr. Ellis called Label and Damning. It’s “blatant overgeneralization” – calling an apple bad simply because it has a bruise, or a barrel bad because it has a few bad apples. It's what neo-Nazis and white supremists do. It's what racists do. But it's what a lot of others do as well regarding those folks. It’s human nature to attend more to differences between us and others, and to attach undue and unhelpful importance to those differences. I've always believed we're hardwired to do so from our distant past when it meant life or death more than it does today. But that’s also what has always driven and sustained conflicts, and why it’s irrational. It only makes peoples’ lives worse than they need to be. That never makes sense. There’s a lot of that going on today. The conflict in Charlottesville was an acute example of it. But it's generally true of our political and ideological discourse in this country. It has been forever, but it's worse than ever today, probably because of the effect of having more media than ever.
There’s nothing wrong with tactfully challenging others. It’s often important we do. Like when they have racist beliefs and expouse them openly. But we never can control what others think, feel, say or do, and labeling and damning those we disagree with won’t get them to consider changing. They usually just irrationally double down on their beliefs in self-defense. Neo-Nazis have some quite irrational demands, i.e. that races should be separated. It's irrational because it's never going to happen, they don't have the power to make it happen, and it just inflames them to cling to such demands. That needs to be challenged, for all our sakes.
But we're never going to agree on everything, and if we’re ever going to find a way to live side by side when we disagree, choosing to have UOA is step we need to take, even if others are unwilling. Perhaps if we do, they might be more likely to follow. The other route is to become "antifa", and that's just going to make an already bad situation even worse for all of us.