Once people were farming the same land season after season, private property quickly replaced communal ownership as the modus operandi in most societies.

We're all members of one tribe or another—bonded by culture, family, religion, class, education, employ-ment, team affiliation, or any number of other criteria. An essential first step in discerning the cultural from the human is what mythologist Joseph Campbell called detribalization. We have to recognize the various tribes we belong to and begin extricating ourselves from the unex-amined assumptions each of them mistakes for the truth.

Especially when we're talking about intimate, personal, biological experiences like eating or having sex, we mustn't forget that the familiar fingers of culture reach deep into our minds. We can't feel them adjusting our dials and flicking our switches, but every culture leads its members to believe some things are naturally right and others naturally wrong. These beliefs may feel right, but it's a feeling we trust at our own peril.

With uprising of agriculture, land could now be possessed, owned, and passed down the generations. Food that had been hunted and gathered now had to be sowed, tended, harvested, stored, defended, bought, and sold. Fences, walls, and irrigation systems had to be built and reinforced; armies to defend it all had to be raised, fed, and controlled.

With agriculture, virtually everything changed: the nature of status and power, social and family structures, how humans interacted with the natural world, the gods they worshipped, the likelihood and nature of warfare between groups, quality of life, longevity, and certainly, the rules governing sexuality.

Foragers divide and distribute meat equitably, breastfeed one another's babies, have little or no privacy from one another, and depend upon each other for survival. As much as our social world revolves around notions of private property and individual responsibility, theirs spins in the opposite direction, toward group welfare, group identity, profound interrelation, and mutual dependence.