I’m actually a little puzzled by this week’s question, because it makes a presumption that I’m not convinced is true: How do adult authors write from the point of view of children/teenagers so well?
So let me ask the obvious: do they? I can’t really think of any examples right now, but I’m sure I’ve read books with a teenage character that seemed far too mature (or childish) to me. The reason I can’t remember any is probably because I abandoned them halfway through – I’m not a huge fan of YA at the best of times, never mind bad YA.
Anyway. Setting aside that obvious flaw in the question, let’s tackle the obvious answer: every adult author was once a child, and may therefore remember very well what it felt like. Alternatively they have a child/children, and can observe on a day to day basis what they’re like.
Third alternative, if – like me – you honestly cannot remember what it felt like to be a child, and have no children of your own, there are always other people’s children. Nephews, nieces, friends’ children, you get the picture. Also: imagination! The writer’s biggest asset.
Lastly, this assumption is also subjective. Like dialogue, what one reader will perceive as a perfectly believable conversation, another reader will think is full of pretentious words that no sane person would ever use when talking to someone else. Say that you have a sixteen-year-old hero(ine) in a fantasy novel, who (through circumstances beyond his/her control, of course) is forced to take up the mantle of authority and lead an army into battle. If this hero(ine) is very mature it could be plausible if the world is harsh and forces children to grow up quickly. However, if this is a fish-out-of-water fantasy novel where the hero(ine) has somehow been transplanted into this world from twentieth century Europe/America/your continent of choice, I’d be more sceptical if they were very mature. It’s all about context.
I’d also imagine that the author has beta readers who will tell them when children don’t sound realistic.
Original post with other authors’ answers can be found here on Jay Dee’s blog.