But various anthropologists have pointed out that this barter economy has never been witnessed as researchers have traveled to undeveloped parts of the globe. “No example of a barter economy, pure and simple, has ever been described, let alone the emergence from it of money,” wrote the Cambridge anthropology professor Caroline Humphrey in a 1985 paper. “All available ethnography suggests that there never has been such a thing.”

Humphrey isn’t alone. Other academics, including the French sociologist Marcel Mauss, and the Cambridge political economist Geoffrey Ingham have long espoused similar arguments.

When barter has appeared, it wasn’t as part of a purely barter economy, and money didn’t emerge from it—rather, it emerged from money. After Rome fell, for instance, Europeans used barter as a substitute for the Roman currency people had gotten used to. “In most of the cases we know about, [barter] takes place between people who are familiar with the use of money, but for one reason or another, don’t have a lot of it around,” explains David Graeber, an anthropology professor at the London School of Economics.

So if barter never existed, what did? Anthropologists describe a wide variety of methods of exchange—none of which are of the “two-cows-for-10-bushels-of-wheat” variety.

Communities of Iroquois Native Americans, for instance, stockpiled their goods in longhouses. Female councils then allocated the goods, explains Graeber. Other indigenous communities relied on “gift economies,” which went something like this: If you were a baker who needed meat, you didn’t offer your bagels for the butcher’s steaks. Instead, you got your wife to hint to the butcher’s wife that you two were low on iron, and she’d say something like “Oh really? Have a hamburger, we’ve got plenty!” Down the line, the butcher might want a birthday cake, or help moving to a new apartment, and you’d help him out.

On paper, this sounds a bit like delayed barter, but it bears some significant differences. For one thing, it’s much more efficient than Smith’s idea of a barter system, since it doesn’t depend on each person simultaneously having what the other wants. It’s also not tit for tat: No one ever assigns a specific value to the meat or cake or house-building labor, meaning debts can’t be transferred.

And, in a gift economy, exchange isn’t impersonal. If you’re trading with someone you care about, you’ll “inevitably also care about her enough to take her individual needs, desires, and situation into account,” argues Graeber. “Even if you do swap one thing for another, you are likely to frame the matter as a gift.”

Trade did occur in non-monetary societies, but not among fellow villagers. Instead, it was used almost exclusively with strangers, or even enemies, where it was often accompanied by complex rituals involving trade, dance, feasting, mock fighting, or sex—and sometimes all of them intertwined. Take the indigenous Gunwinggu people of Australia, as observed by the anthropologist Ronald Berndt in the 1940s:

Men from the visiting group sit quietly while women of the opposite moiety come over and give them cloth, hit them, and invite them to copulate. They take any liberty they choose with the men, amid amusement and applause, while the singing and dancing continue. Women try to undo the men’s loin coverings or touch their penises, and to drag them from the “ring place” for coitus. The men go with their … partners, with a show of reluctance to copulate in the bushes away from the fires which light up the dancers. They may give the women tobacco or beads. When the women return, they give part of this tobacco to their own husbands.

So it’s a little more complicated than just trading a piece of cloth for a handful of tobacco.