Thomas

“Marriages among the Arunta were frequently arranged between two men, one of whom had just fathered a baby boy and the other a baby girl. When two such men met to arrange a marriage, however, the union they were arranging wasn’t between those two babies—it was much too late for that, because the baby girl’s marriage had already been arranged. Rather, the two fathers were agreeing that the baby boy would marry the first daughter of the baby girl. That is, they were agreeing that the infant girl would become the mother-in-law of the infant boy.”
― Alvin E. Roth, Who Gets What — and Why: The New Economics of Matchmaking and Market Design