A brain partly made of tangled roots and branches, with one side neat and structured ("instinct") and the other wild and flowering ("plasticity")

Instincts, plasticity, and the messy truth about nature vs. nurture

The idea that creatures, humans included, are governed by hardwired instincts is a comforting one. It suggests order, predictability, and perhaps even an excuse for that inexplicable urge to hoard snacks. But biology, as usual, refuses to play along neatly. Instead, we find that so-called “instincts” are often more like rough drafts, heavily edited by experience, environment, and even the ghostly hand of epigenetics. The myth of the unshakable instinct ...

June 4, 2025 · 5 min