Wing Woo Gar
Senior Master
Well said.Well, most people don't think too much about what they think. In the case of Willis vs Moranis, their impression would likely be based on physical size and the nature of the roles they've played. Also there could be the number of times they've smiled, and how they play status in a performance sense (e.g. high status = less movement).
I agree that words are often inadequate as in describing music or art, but being unable to explain our attitudes doesn't always mean that we can't trace the history of how we acquired that attitude. Over time, the attitude moves from explicit to implicit, in the way that an expert athlete doesn't think about what they do; they just do it.
That's why we can sometimes throw an expert off their game by complimenting them at a "micro" level: "hey that was a great way that you grip that racquet: very Continental!" Doing so, if the recipient is open, can shift their skills back to the explicit level, and hopefully throw them off by causing them to lose some of the implicit integration they earned in the years after they learned the Continental grip. In other words, while that player might not be able to articulate all the steps that got them to where they were, they did pass through those steps on the way to expertise.
So we can definitely trace a person's perception to their likely influences, once we know what those are. "I know it when I see it" is a case of the explicit influences becoming an implicit attitude or opinion.
... but we should not assume that an opinion is always an accurate perception. no matter how confident the holder of that opinion is.