Very interesting! I happen to know of some other problems: Heat and cross-brain communication time. Bird brains are much smarter than we are per weight and vo

Very interesting! I happen to know of some other problems: Heat and cross-brain communication time. Bird brains are much smarter than we are per weight and volume. Not a little bit, but a lot. I think part of the reason they can do that is that they have much better cooling because their heads are small. Having a bigger brain than we do means that it would need to have a lower activity level because of cooling constraints. There's also diminishing returns from size because the interconnects from one point in the brain to another have longer latency. One response to this is to fold the brain, as we do. Regardless, at some point adding more volume stops making sense.