This book is a data-rich study of instances of pica – or, in the Young’s words, “the craving and subsequent consumption of non-food items.” Young is a nutrition scientist and anthropologist, and her study focuses mainly on contemporary demographics practicing pica, but she frequently brings in literary and historical examples to illustrate the cultural contexts of pica. (There is also an appendix of pica scenes in literature, which gives the literary food scholars among us an additional reason to pick up the book.) This is definitely a scientific book, but Young is very clear that the act of eating (anything, but particularly non-food substance) cannot be fully understood as an isolated act of nutrition-seeking. Eating is embedded in social networks (both local, like friendships, and wide, like region), in systems of belief about what food is and what kinds of food are good or bad to eat, in personal experience as well as biological imperative.
The task of “understanding” pica seems to take two forms. For one, this book provides a strong and broad description of pica practices. Pica is incredibly widespread, occurring in every culture on every continent, and there are examples cited throughout history. Craving Earth focuses on a few of the most common types, which are (in roughly descending order): earth (esp. clay), cornstarch, large quantities of ice, chalk, and charcoal. “Craving,” in the definition I gave above, is key to separating pica from, say, a child’s exploratory mouthing, or a more compulsive disorder such as trichophagia: people who practice pica typically desire their particular substance, and may go out of their way to obtain the best kind of clay or the ice with the right texture. (Young cites users of an ice-chewing website who swap tips. Sonic’s ice is well regarded in this community.)
The other part of “understanding,” of course, means asking the question “why.” Several chapters address previously floated hypotheses about pica – some scientific, some so-called “common sense,” and several contradictory. For each hypothesis, Young tests out several predictions that could be made if the hypothesis were true. For example, a relatively benign belief about some forms of pica (particularly earth and chalk) is that people do it to obtain nutrients they otherwise lack. If so, Young argues, we’d be able to observe the following: pica would be associated with micronutrient deficiency; pica would disappear when the deficiency disappears; the pica substance might be proven to supply a missing nutrient to a body. In this particular case, none of these predictions turned out to be true enough of the time to validate the hypothesis.
That is of many of the hypotheses suggested by Young and other sources: only a few are definitively true or false, and most are sometimes true or require further testing. This may sound inconclusive, but actually it’s perfect: it’s far more useful to have a complex and detailed landscape with room for uncertainty than it would be to promote false or flimsy conclusions. This, in fact, does increase the understanding of pica – or at least, it increase my understanding. I admire the methodology: imagine if we applied the same rigor and consideration to other eating and body studies, such as that overdetermined issue of “obesity.” The reportage would be less pathologizing and corrective, more compassionate and descriptive. Craving Earth, then, is a great model as well as a fascinating and informative read.