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THE OPPOSITE OF ENHANCEMENT

The more we learn about the brain, the clearer it has become that all kinds of things change it. On one level, this is so intuitive it borders on the banal; after all, why else do we send our kids to school, or make sure they don’t eat lead paint? But our increasing ability to actually measure those changes, and to unravel the mechanisms that bring them about, has given rise to some unsettling observations. One of the most provocative comes from Martha Farah’s research on the impact of poverty on brain development.

Like a lot of people who get interested in brain development, Martha Farah came to the topic through parenthood. But it wasn’t exactly having a child that fired her curiosity. It was having babysitters. Most of hers came from the other side of the proverbial tracks, and as she got to know them, stark differences became evident between her life and theirs. “Nowhere were the differences more dramatic,” Farah has written, “than in the realm of child development. Their daughters and sons and nieces and nephews began life with the same evident promise as my daughter and her friends. Yet as the years went on, I saw their paths diverge.”

When we got together at a café down the block from her Center City home, I asked Farah about the research this observation had inspired. For the past several years she has been studying several groups of low-income and middle-income children—from kindergarten age through high school—in an effort to get to the bottom of a phenomenon that has perturbed social scientists for decades: the persistence of poverty across generations.

The most recent phase of her work has involved administering cognitive tests to a group of low socioeconomic-status children whose home lives have been documented in detail as part of a different longitudinal study. Farah has grown increasingly convinced that the circumstances of their upbringing have specific impacts on different parts of their brains.

“What we’ve been able to determine,” she says, “is that the kids who grew up in families with relatively little cognitive stimulation [as indicated by the presence of things like toys and books in the home] grow up to have relatively less well-developed language abilities.”

Another finding drilled a little deeper. “Kids who grew up in families with more stress—and less parental nurturance—grew up to have worse memory abilities,” Farah says. “That might seem like a really weird, inexplicable relationship, but it turns out that it’s very consistent with research that’s been done with animals, in which it’s been shown that early parental nurturance buffers the developing brain against the effects of stress hormones that tend to impair the part of the brain that’s responsible for learning and memory.”

Her studies are part of a growing body of work that Farah believes may “recast the disadvantages of childhood poverty as a bioethical issue” rather than a strictly economic one.

“The thing is,” she adds, “as far as the effects of poverty on brain development go, we don’t know to what extent they are reversible. So I think it would be making a big assumption to say, Oh, this kid grew up poor; the reason they are not doing well in school is that their brain was changed by the experience of growing up poor, and so don’t expect much of them. It would be making a big assumption that they couldn’t be helped by the appropriate kinds of remediation. [We may equally well discover] that brains that have undergone one kind of an experience at an early age need another kind of experience at a later age to achieve their full potential. In which case we could use the neuroscience as a sort of rationale for offering them various kinds of experiences that make for something enhancing, or enriching.”

This line of research throws the typical debate over enhancement into sharp relief. As Farah noted in a recent book chapter, “Neuroethicists have rightly called attention to the ethically problematic ability of drugs to change who we are, for example by the effects of certain molecules on certain receptors. It is metaphysically just as perplexing, and socially at least as distressing, that an impoverished and stressful childhood can diminish us by equally concrete physical mechanisms, such as the impact of early life stress on medial temporal memory ability through neuroendocrine mechanisms.”

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