But then Evans and Schamberg did something new: They introduced some biological measures of stress. When the children in the study were nine years old, and again when they were thirteen, Evans’s researchers took a number of physiological readings from each child, including blood pressure, body mass index, and levels of certain stress hormones, including cortisol. Evans and Schamberg combined those biological data to create their own measure of allostatic load: the physical effects of having an overtaxed stress-response system. When they sat down with all the data and compared each child’s Simon score, poverty history, and allostatic-load reading, they found that the three measures correlated—more time in poverty meant higher allostatic-load numbers and lower scores on Simon. But then came the surprise: When they used statistical techniques to factor out the effect of allostatic load, the poverty effect disappeared completely. It wasn’t poverty itself that was compromising the executive-function abilities of the poor kids. It was the stress that went along with it. This was, potentially at least, a big deal in terms of our understanding of poverty. Picture two boys sitting together playing Simon for the first time. One is from an upper-middle-class home, and one is from a low-income home. The kid from the upper-middle-class home is doing a lot better at memorizing the patterns. We might be inclined to assume that the reason for this effect is genetic—maybe there’s a Simon gene that rich kids are more likely to possess. Or maybe it has to do with material advantages in the upper-middle-class kid’s home—more books, more games, more electronic toys. Or maybe his school is a better place to learn short-term memory skills. Or perhaps it’s some combination of the three. But what Evans and Schamberg found is that the more significant disadvantage the low-income boy faces is in fact his elevated allostatic load. And if another low-income boy came along with low levels of allostatic load—if, for whatever reason, he had had a less stressful childhood, despite his family’s poverty—he would in all probability do just as well at the Simon competition as the rich kid. And why does a low Simon score matter? Because in high school, college, and the workplace, life is filled with tasks where working memory is crucial to success.
To achieve better equality in economic outcomes, the key is to ensure that children in low-income situations do not undergo the stresses that arise from financial insecurity. Of course, just because there is isn’t any financial woes dosen’t mean that children would have perfect, stress-free childhoods. However, financial insecurity is the biggest factor we hvae now and if more effort could be put in place to help families in poverty, we can give these kids a much better chance in the future and increase social mobility.
