True in the sense that some aspects of individual psychology is fixed by that point, I suspect, but not in other ways. I could go check a textbook on my shelves about what’s largely determined by age 15, but it’s 2am now! I still have a few traits I had when I was 15, though by 18 I was a very different person. And at 15 I hadn’t had many of the life experiences that inform my writing (when I get the chance to write – just over 100 words today in between emails, a rescheduled doctor’s appointment, last-minute Xmas shopping, fixing broken Xmas lights and an impromptu visit to a friend).
True enough. And if we’re talking about maturity and craft, I’d even argue that few people under the age of 30 are ready to write serious fiction. (Even the most brilliant novels by writers in their twenties tend to read like extended impersonations of other books.) But if we’re talking about the basic emotions that authors tend to engage (love, hate, envy, guilt), then I think it’s true that most of the essential materials are in place by age 15. Or even 5.
Indeed. I get the impression this discussion could turn into a debate on the relative merits of Freud, Jung and Adler and their respective views on the significance of early childhood experiences on adult personality…
Alec Nevala-Lee 
True in the sense that some aspects of individual psychology is fixed by that point, I suspect, but not in other ways. I could go check a textbook on my shelves about what’s largely determined by age 15, but it’s 2am now! I still have a few traits I had when I was 15, though by 18 I was a very different person. And at 15 I hadn’t had many of the life experiences that inform my writing (when I get the chance to write – just over 100 words today in between emails, a rescheduled doctor’s appointment, last-minute Xmas shopping, fixing broken Xmas lights and an impromptu visit to a friend).
Jon Vagg
December 21, 2010 at 8:10 pm
True enough. And if we’re talking about maturity and craft, I’d even argue that few people under the age of 30 are ready to write serious fiction. (Even the most brilliant novels by writers in their twenties tend to read like extended impersonations of other books.) But if we’re talking about the basic emotions that authors tend to engage (love, hate, envy, guilt), then I think it’s true that most of the essential materials are in place by age 15. Or even 5.
nevalalee
December 21, 2010 at 8:43 pm
Indeed. I get the impression this discussion could turn into a debate on the relative merits of Freud, Jung and Adler and their respective views on the significance of early childhood experiences on adult personality…
Jon Vagg
December 21, 2010 at 9:19 pm
Just as long as we don’t involve Melanie Klein!
nevalalee
December 21, 2010 at 10:17 pm
(shudder) I’m with you on that one!
Jon Vagg
December 22, 2010 at 5:14 am