Comment by Graham Bower (graham-bower) on Are big brains for processing sensory input? · 2022-12-30T13:15:27.768Z · LW · GW

My guess is just that evolution is dumb. Larger brains are less efficient (compared to small brains like birds have), but the cost of a less efficient brain is not so heavy in larger creatures, so there has been less selective pressure for brain efficiency in larger creatures.