David Brooks rightly holds that the evolutionary picture of human nature is inadequate:
[The] strictly evolutionary view of human nature sells humanity short. It leaves the impression that we are just slightly higher animals — thousands of years of evolutionary processes capped by a thin layer of rationality. It lops off entire regions of human possibility.
According to Brooks, evolutionary biologists have reduced human nature to two distinct systems, one “to procreate or strut or think in certain ways” and another focused on reason and consciousness. Although biology depicts this dual nature, Brooks recognizes that morality mostly consists of reason ordering our more animalistic impulses:
Deep down we are mammals with unconscious instincts and drives. Up top there’s a relatively recent layer of rationality. Yet in conversation when we say someone is deep, that they have a deep mind or a deep heart, we don’t mean that they are animalistic or impulsive. We mean the opposite.