The cerebral cortex is a liberation. We need no longer be trapped in the genetically inherited behavior patterns of lizards and baboons. We are, each of us, largely responsible for what gets put into our brains, for what, as adults, we wind up caring for and knowing about. No longer at the mercy of the reptile brain, we can change ourselves.

The brain must function during the renovation […] The old parts are in charge of too many fundamental functions for them to be replaced altogether. So they wheeze along, out of-date and sometimes counterproductive, but a necessary consequence of our evolution.

MacLean has shown that the R-complex plays an important role in aggressive behavior, territoriality, ritual and the establishment of social hierarchies. Despite occasional welcome exceptions, this seems to me to characterize a great deal of modern human bureaucratic and political behavior.

Those mothers with hereditary large pelvises were able to bear large-brained babies who because of their superior intelligence were able to compete successfully in adulthood with the smaller-brained offspring of mothers with smaller pelvises.