I think I've always known this. I remember watching the early seasons of "The Waltons" and my Dad, who remembered the Great Depression, refusing to watch. "It's a lie," he'd say. "They want to show you this family closing ranks and prospering despite their poverty, but the reality is that being poor tears families apart." Late I encountered Ruby Payne's work on the culture of poverty, and it reinforced what my Dad had said; everything I saw there matched to everything I saw in the real world. But now it turns out that there may be measurable cognitive deficit associated with being in poverty. Here's what a Princeton study recently published in Science shows : In a series of experiments, the researchers found that pressing financial concerns had an immediate impact on the ability of low-income individuals to perform on common cognitive and logic tests. On average, a person preoccupied with money problems exhibited a drop i