Some people can't see mental images

I’ve read tons of these and still have no idea if I have aphantasia or not. I can’t understand whether people just have different ways of describing what’s in their minds eye or if there’s really a fundamental difference.

Yep. Problem is that there's actually a spectrum of vividity of mental imagery, but in popular discussion it's always seen as a binary on/off thing.

An old post by Scott Alexander (16+ years, mind blown) discusses this, long before the term "aphantasia" became a thing [1]. There was a debate about what "imagination" actually means already in the late 1800s; some people were absolutely certain that it was just a metaphor and nobody actually "sees" things in their mind; others were vehement that mental images are just as real as those perceived with our eyes. The controversy was resolved by Francis Galton, who did some rigorous interviewing and showed that it really does vary a lot from person to person.

[1] https://www.lesswrong.com/posts/baTWMegR42PAsH9qJ/generalizi...

Comically, though, programming communities really seem to have a statistical over representation of both aphantasics and hyperphantasics. One of these articles comes out every few years and I've witnessed at numerous workplaces how quickly a large portion of the engineers realize they're aphantasic and everyone else is aghast that they can't rotate complete architectural diagrams etc.

That said, it really is binary or not whether you cannot see images at all in your head and there are, in fact, some very real downsides related to episodic memory. As someone who realized I was aphantasic late in life, I think it's pretty important to realize you are if in fact you are---ideally as early in your educational process as possible. For everyone else, it's interesting to realize some people have more vivid imagery than you and some people less, but probably that doesn't change very much about your life.

> I think it's pretty important to realize you are if in fact you are---ideally as early in your educational process as possible.

Is that because it’s hereditary or instead something that was missing in early childhood? Like as a toddler you were never given one of those games where you fit shapes into different sized holes for example?

I think it’s because you can find supports to help you learn.

I’ve been teaching math for almost 18 years at this point, and only a couple years ago learned that I lean towards aphantasia. Back in high school, geometry was HARD. Calc 3 was HARD. It was presented as visualize and imagine, and I tried my best. It just turns out other people could do that, and the fuzzy thing thing (or, more commonly, the ‘bulleted list of information’ that make up my imagination) was not “normal.”

If I’d known this (and my teachers were in a position to also know this), then maybe we’d spend more time with external visual models (what Geogebra now does for us, for example) to help me out.

Now that I teach future high school math teachers, it’s definitely something I talk about to normalize “not everyone can see in their mind.”