To build an AI requires less computation power, how does one throw less computation power and still achieve similar or better results than humans?

The answer is in the constraints. Humans are able to take an infinite number of ways to act and boil it down to one, an actuality. Thus, an AI should be able to do the same. Humans are constrained by their environments, mental knowledge (imitation), and identities… how does one constrain an AI then with code?