Just pull yourself up by the bootstraps and it'll all be fine!

The stress of growing up in a poor and unstable household affects children as young as 9 years old on a genetic level, shortening a portion of their chromosomes that scientists say is a key indicator of aging and illness, according to a study released Monday. The researchers say their findings are the first that document this type of genetic change among minority children and make a strong case for the importance of early-childhood intervention in vulnerable communities.

Researchers examined the DNA of a small group of 9-year-old African-American boys who had experienced chronic stress as a result of growing up in families with poor socioeconomic status. They found that the boys’ telomeres were shorter than those of boys the same age and ethnicity who came from advantaged families.

Telomeres are repetitive sequences of DNA found at the ends of chromosomes that function as a sort of cap to protect the genetic information when the DNA replicates. The telomeres become shorter each time DNA replicates, and studies have shown that stress accelerates that shortening, serving as a sort of genetic weathering that’s similar to aging.

The scientists were surprised to find significant associations between the shortening of the boys’ telomeres and low family income, low levels of maternal education, family instability and a harsh parenting style, compared with boys who came from higher-income and more stable and nurturing backgrounds. In addition, disadvantaged boys who had a genetic sensitivity to dopamine and serotonin — neurotransmitters connected with happiness and feeling pleasure — experienced accelerated shortening of their telomeres, pushing them farther down the road toward stress and sickness.

“Originally, I think we thought that we’d see it with the mothers of these kids,” said Colter Mitchell, lead author of the study and a faculty research fellow at the University of Michigan’s Population Studies Center and Survey Research Center. “But I think more surprising is that we see it as young as 9.”

I read another report last week that said half of all New York City teens behind bars have a brain injury. Whatever! It's not as if they have affluenza.

And so it goes.