Inference

One of my favourite illusions is the stopped clock effect, also known by the much cooler name chronostasis. The illusion happens when you see a clock out of the corner of your eye, then turn your eyes to focus on it. The amount of time it takes the next second to pass seems much longer than a second. What's happening is that during the time you couldn't actually make out the face of the clock, your brain fills in what it thinks should be there. That illusion is normally seamless, except that clocks have to obey more stringent rules that your visual system doesn't know how to fake.

I've been thinking about a similar illusion I've noticed in areas I don't often think about directly. I recently had a long conversation with a hair stylist about the complexities of the salon industry and most of the time I spent just convincing myself that people could legitimately care this much about hair. I remember being younger and thinking, like young people do, that I must have just about figured out everything worth figuring out. It turns out to be a pretty common sentiment.

I think part of the reason we often understimate how much we don't know is that we are so very good at just filling in the blanks with whatever available information we can get our hands on. If you look at the frankly crap signal we get before all our neurological trickery, it's amazing we can see at all. Hundreds of years ago, Helmholtz arrived at the same conclusion, which he called unconscious inference.

Our thinking is similarly amazing for how much it gets done with so little. Our tiny capacity for focus and working memory only really becomes obvious when we go looking for it, for example in specifically designed tasks like N-back. Part of this is that our brain is just well adapted to the kinds of problems we tend to have, but I think it's also that our mental capacity, like our vision, is particularly good at hiding its own limitations. I once saw someone ask "what do you see if you're completely blind?", and a blind person replied "well, what do you see behind you?"

So not knowing what we don't know isn't entirely surprising, but what does surprise me is how hard it is to even think about. Even once you build up an intuition for "there are probably a bunch of things I don't know", it seems like it doesn't actually work very well. When you're paying attention it's easy to remember, but it's the things you're not paying attention to that are the problem.

But perhaps this particular quirk is inevitable. As long as we have a limited capacity, there has to be some behaviour when that capacity is exceeded. While we might assume that a big obvious "your capacity has been exceeded!" signal would be better, the reality is that our perception and understanding is in a constant state of compromise, and if there was such a signal it would be going off constantly.

Maybe it's for the best that we don't notice.