What if, in trying to figure out the best way to lead our lives, we could conduct tests on the different methods?

According to author Jared Diamond, such trials are already taking place. In his new book, “The World Until Yesterday,” Diamond argues: “Traditional societies in effect represent thousands of natural experiments in how to construct a human society. They have come up with thousands of solutions to human problems” – solutions, he points out, that are different from those adopted by modern, industrialized societies.

Diamond, who wrote the Pulitzer Prize-winning “Guns, Germs, and Steel” and is a geography professor at UCLA, warns against romanticizing and idealizing the past, while encouraging readers to consider that some traditional practices may be a better fit for us. What follows is an extensive, textbooklike examination of issues ranging from conflict resolution to treatment of the elderly, language diversity to salt intake.