The calories we use for computing are shared with the rest of the body and are bounded by how much we can practically metabolize. Every cognitive feature fights with every other cognitive feature for fuel.

The number of neurons in our brain is roughly fixed at birth, and so any faculties that require more neurons in one region necessarily take away neurons from other regions. Having enhanced numeracy, for example, should correspond to a decline in some other cognitive faculty, unless the total neurons are increased, which requires yet more calories.