Work hard, get ahead — or so goes the assumption. Policymakers are building character training into school curriculums in places with low incomes and high crime, in hopes that kids will learn to work hard and aim high. Though this seems like a logical step, researchers at Northwestern have found that the extra effort these kids will have to put in, combined with the socioeconomic odds they’re up against, could take a huge toll on their health.

The researchers, who published their work in Proceedings of the National Academy of Sciences, studied levels of self control and physiological changes in 292 black teenagers living in rural Georgia, keeping a close eye on kids who seemed especially tenacious. The study found that the students who had the most self-control also showed the most rapid signs of aging — which they measured by looking at DNA methylation, a natural process that reveals differences between biological and chronological age. The kids’ cells looked a lot older than they should’ve, given their age. This wasn’t the case for kids who were higher up on the socioeconomic ladder. For them, having high self-control was only a positive thing.

Is it worth it, then, for these kids to put in more effort and to practice self-control? Ideally, of course, these kids wouldn’t have to balance the two, but the social and economic factors they’re up against have deep roots. In an analysis of the Northwestern data. The Atlantic brings up “John Henryism,” a term coined by the public health researcher Sherman James in the 1970s to describe the strategy of putting in immense amounts of effort to cope with social stresses such as racism. James studied why black North Carolinians had a disproportionately high rate of heart disease and strokes. The term was meant to describe the immense amount of effort black Americans put into their daily lives “not merely to make ends meet … but to leave something behind,” as James put it. It’s the idea that, compared to their white counterparts, black kids need to put in as much work and then some, to make up for the expectation — whether real or perceived — that they can’t.

It’s a complicated problem to address — one that neither science nor policy can handle on its own. But studies like this are a start.