Humans are both predatory and cooperative. Jonathan Haidt, whose works on moral psychology include The Righteous Mind, says that we are “90 percent chimp, 10 percent bee.” Chimpanzees are violent and competitive, with little ability to cooperate. Bees coordinate effectively and seem willing to sacrifice for the sake of the hive.
Much political theory follows Thomas Hobbes, who wrote that living without a government would mean enduring a “war of all against all.” Without an overriding authority, the chimpanzee component of human nature would not permit us to live peacefully with one another.