You always have to be careful when drawing conclusions about causality from observational studies. > New research sounds a particularly disquieting note. A maj

You always have to be careful when drawing conclusions about causality from observational studies. > New research sounds a particularly disquieting note. A major evaluation of Tennessee’s publicly funded preschool system, published in September, found that although children who had attended preschool initially exhibited more “school readiness” skills when they entered kindergarten than did their non-preschool-attending peers, by the time they were in first grade their attitudes toward school were deteriorating. And by second grade they performed worse on tests measuring literacy, language, and math skills. The researchers told New York magazine that overreliance on direct instruction and repetitive, poorly structured pedagogy were likely culprits; children who’d been subjected to the same insipid tasks year after year after year were understandably losing their enthusiasm for learning. Without knowing more about this study, it seems vastly more likely that sociological differences between the preschool and non-preschool groups explain this difference.