Success: What counts more is productivity

To be fair, other studies show age does matter sometimes: maths favours the young; and physical pursuits, such as ballet or athletics, aren’t exactly welcoming to the achy-kneed. Personality also influences the age at which success strikes. The economist David Galenson splits creative geniuses into “conceptual” prodigies such as Picasso – who burst on to the scene with a radical new viewpoint – and “experimental” ones such as Cézanne, whose brilliance emerges through trial and error. (In his podcast Revisionist History, Malcolm Gladwell applies the Cézanne model to Leonard Cohen’s song Hallelujah, which sounds as if it popped into existence as a perfect gem, yet went through years of being turgid.) But even Galenson’s work implies age matters little. He once polled literary scholars to make a list of America’s 11 most important poems, then looked up the ages at which they’d been composed: a wide span, from 23 to 59