The food disaster photo is a standard feature of babyhood. It’s also, it turns out, pretty much emblematic of the way we’re now supposed to encourage babies to eat. Known as “baby-led weaning,” this practice holds that feeding babies—once they’re old enough to chew—is an activity best left to the babies themselves. And it’s all about fingers, rather than spoons and commercial baby food.

Baby food came about because infants couldn’t always be supplied with breast milk. The earliest of artificial baby foods were milk substitutes, desperate alternatives for milk-less mothers or mother-less babies. Primitive baby bottles date back at least 2,000 years. These were oblong clay vessels with spouts, sometimes sadly found in infant graves. (They baffled archaeologists, who identified