[frankinstien]

An interesting fact about dolphins, they have to consciously think about breathing. With that said; how can a dolphin sleep without drowning? Answer: They sleep half of their brain at a time.  When they do sleep one hemisphere the eye that the hemisphere controls closes while the other is wide open. So just think how productive a dolphin could be if we could transplant their brain to a robotic body or human body, effectively they don't sleep. one hemisphere could be working while the other is asleep!  Here's an article that explains it.

[MagnusWootton]

If man has enough energy to continually do work without sleeping,  I reckon god would step in to knock him out.

Being a top inventor is 70% energy 30%intelligence, I think,  energy makes it all happen.

[frankinstien]

Just look at the comparison of the dolphin brain to a human brain:



The cerebellum is massive. A pilot whale's neocortex has approximately 37.2 × 10^9 neurons almost twice what humans have.

Here's an article stating that human brains are not more efficient than any other mammalian brain.

[MagnusWootton]

Men have bigger brains than women on average,  does that mean they are smarter?

Bigger things usually come packed with a bigger brain and bigger doodle,  because otherwise it would be disproportionate.   My vote is its purely aesthetic and has no real featural advantage.

I predict::
Nature has very sneaky ways of making things smarter,  and the size of the brain becomes a superfluous semantic once u know how intelligence can work really well.