The Importance of Salability in Human Economy

Alale village's ability to organize raids and kidnap a woman from an alien community seems to have been the key to its ability to start trading women for money. To make something salable in human economy, one needs to first rip it from its context. That's what slaves are, people stolen from the community that made them what they are. As strangers to their new communities, slaves no longer had mothers, fathers, kin of any sort. This is why they could be bought and sold, or even killed - because the only relation they had was to their owners.