Scratch that. I’ve put a bit more thought into it.
Primates can throw but not catch. More to the point, they can accurately hit things with projectiles, but they are considerably worse at anticipating the trajectory of an incoming projectile, (c.f. “chimps can’t juggle”).
Being a quadratic shape, calculating an intercept of a projectile’s parabolic trajectory would require a square root operation. Our brains can’t natively do that, so they need to cheat.
In order to anticipate where a parabolic projectile is going to land, you need to see it in motion a fraction of a second before or after the apex of its curve. (Disclosure: I’ve read this fact somewhere I trust but for the life of me can’t remember where). Then you can just treat it as a falling object with a constant horizontal velocity, and no square root is required. Since the parabola’s symmetrical about its apex, you can plot its entire path provided you know where its apex is, what gravity’s like, and how fast it’s going horizontally.
That explains catching, but how the hell does throwing work? That requires a complete projection of the parabola, which is presumably some sort of spandrel from the catching heuristic, so how come chimps can throw but not catch?
Scratch that. I’ve put a bit more thought into it.
Primates can throw but not catch. More to the point, they can accurately hit things with projectiles, but they are considerably worse at anticipating the trajectory of an incoming projectile, (c.f. “chimps can’t juggle”).
Being a quadratic shape, calculating an intercept of a projectile’s parabolic trajectory would require a square root operation. Our brains can’t natively do that, so they need to cheat.
In order to anticipate where a parabolic projectile is going to land, you need to see it in motion a fraction of a second before or after the apex of its curve. (Disclosure: I’ve read this fact somewhere I trust but for the life of me can’t remember where). Then you can just treat it as a falling object with a constant horizontal velocity, and no square root is required. Since the parabola’s symmetrical about its apex, you can plot its entire path provided you know where its apex is, what gravity’s like, and how fast it’s going horizontally.
That explains catching, but how the hell does throwing work? That requires a complete projection of the parabola, which is presumably some sort of spandrel from the catching heuristic, so how come chimps can throw but not catch?