Is age a sufficient indication of expected knowledge level?

Question

This question stems from a few issues and similar meta topics.

Probably the best meta reference for this would be the question Is an asker's age relevant?; I consider this to be somewhat of a follow-up on this. This is different though, where that question and answers focused on keeping that age information in the question. This question is about only having age as the indication of knowledge level.

Basically, my question is; is the age of the asker alone enough to indicate the level of knowledge we should be answering the question at?

I'm prompted to ask this based on the (original version of) this question; where OP was asking how to explain that we can now see atoms to a 4 year old.

It's my personal opinion that in the original format, such questions would be considered opinion based. That's because we don't really know what level of physics knowledge the 4 year old has; and (as shown in the answers) users have quite different interpretations of what a 4 year old is capable of understanding. There are multiple ways to resolve this, such as by being more explicit with the level of knowledge, or by removing those restrictions completely.

It became pretty clear that many members of the community consider these questions perfectly acceptable; but I would love to have a clear consensus on this, instead of just discussion in the comments of the question.

Answer 1

I would say that an age alone does give a reasonable indication of what level we should be targeting, up to maybe 16 or so. When someone asks "how would I explain this to a 4-year-old?" I think we should take that as referring to an average 4-year-old in "Western" society (noting that this site primarily targets English speakers). We don't need to dig into the background of the asker's child or whoever they have in mind. If their child is unusually knowledgeable, then they should be looking for answerers targeted at, say, an 8-year-old instead, or whatever is appropriate.

Answerers may have varying impressions of what a 4-year-old can understand, but I think that's fine. It just means that some answers will under- or overshoot the mark as far as what level of sophistication is expected, which makes some answers better for the asker and others worse, just as with every question. And, as with every question, some answers that are less useful for the asker may be more useful for other readers. That's entirely normal.