“Poets peak young,” the creativity researcher James Kaufman maintains. Mihály Csíkszentmihályi, the author of “Flow,” agrees: “The most creative lyric verse is believed to be that written by the young.” According to the Harvard psychologist Howard Gardner, a leading authority on creativity, “Lyric poetry is a domain where talent is discovered early, burns brightly, and then peters out at an early age.”
I don't know who these idiots are, or where they came from. (I think Howard Gardner said similarly dumb shit in Gladwell's previous article about scientific creativity.) But their claims are utterly risible and anyone who knows anything about lyric poetry, or literature, knows this. This point is important because he uses the counterintuitiveness of his result to launch the (very silly) claim that he and his favorite researchers have discovered a new type of late-flowering artistic genius.
In fact, very few poets produce their best work at first, and by far the most common type in English poetry is the "prodigy" that turns into a "late bloomer." Yeats was a talented minor poet who randomly turned at 50 into a very major poet. A lot of Eliot's best stuff is in Four Quartets, which he wrote when he was over 50. There are a couple of cases of "late blooming," like Stevens, but these are mostly cases of people who took a little longer to find their voice -- or, more plausibly, started later. But all major poets take a few years to find their voice -- even freaks like William Blake and prodigies like Auden, whose juvenilia (200 pp. written age 15-19) Gladwell would have done well to read. The normal course is for poets to start off good, then get better, then get senile and die. There isn't anything remotely mysterious about this.
I haven't got the energy to debunk the rest of the piece but I wish someone would. In particular, I hate how the examples are cherrypicked. Here's a contrast to set against his two writers: Shakespeare was a late bloomer who wrote all of his greatest plays after 35 -- most after 40 -- while Ben Jonson was a prodigy who wrote his last great play (with one possible exception) when he was 35. As to the amounts of research they put into their efforts, and as to their relative sloppiness, I refer you to the historical record.