Is that a good comparison? How often does the average person actually see either of those things? The reason it's surprising that people struggle to draw bikes from memory is that most of us see them all the time.
How about drawing faces of famous people then? Presumably those results would be even worse. With these bicycle drawings, even the most inaccurate ones are pretty easy to recognize as bicycles. But I don’t think you’d get very many recognizable pictures of famous faces, except for a few subjects with famously recognizable features (like hairdo or facial hair).
I think that has more to do with being able to draw. As I argued in another comment here, I think sketching a bike has nothing to do with drawing skills. But sketching a face is not enough: the level of detail that goes into a face is much more sophisticated than a bike. On a bike you connect the lines right and you're good, but in a face... there is no logical, mechanical structure to it that you can easily replicate. The proportions all have to be right, the way skin falls... I think that's different.
I don’t know if I agree with the distinction. Both require you to simplify the actual appearance down to something that will be recognizable. For a bicycle, that’s just a few circles and lines, but skilled artists can draw recognizable faces with the same simple elements.
If you're ten percent off with each bike line, it looks almost perfect. If you're ten percent off with each line while trying to draw a specific person, it won't even resemble them.
A caricature is one thing, and might be doable by an average person, but knowing how to do a caricature is a skill all by itself. A portrait is extremely art skill intensive.
I agree with that, but that’s just the difference between drawing a specific person versus drawing any bicycle. I suspect if you wanted to draw a bicycle that was recognizable as a specific type or brand of bicycle, small differences would be important.
How a bike fits together it's kind of irrelevant for most people, even if you ride one or if you must dodge one.