Does a Bigger Brain Mean More Neurons and Higher IQ? Within species like humans where neurons are roughly the same size, bigger brains likely have more neurons rather than just bigger cells—the chief source of brain volume variation is neuron number, not cell size. Information processing attributes like interconnection capacity scale weakly with neuron size but exponentially with number: 2 neurons = 1 interconnection, but 100 billion neurons = 10^12 possible interconnections. LLMs are essentiall