One reason that the human race will probably not evolve larger brains is that it takes a lot of energy to run such a thinking machine.

Question

Quizplus · Accepted Answer

The brain already consumes a significant amount of energy, accounting for about 20% of the body's energy usage, and as brains get larger, they require even more energy. Therefore, it is unlikely that evolution would favor larger brains if it requires an excessive amount of energy to sustain them.

One Reason That the Human Race Will Probably Not Evolve