Poverty Poisons the Brain

Paul Krugman writes today that “Poverty Is Poison,” building off an article from the Financial Times that discussed last Friday’s session, “Poverty and Brain Development” at the American Association for the Advancement of Science.  Krugman writes: 

As the article explained, neuroscientists have found that “many children growing up in very poor families with low social status experience unhealthy levels of stress hormones, which impair their neural development.” The effect is to impair language development and memory — and hence the ability to escape poverty — for the rest of the child’s life. So now we have another, even more compelling reason to be ashamed about America’s record of failing to fight poverty.

The Financial Times article, “Poverty mars formation of infant brains,” provides some more detail about the impact of poverty through stress, inadequate nutrition and exposure to environmental toxins: “Studies by several US universities have revealed the pervasive harm done to the brain, particularly between the ages of six months and three years, from low socio-economic status.  Martha Farah, director of the University of Pennsylvania’s centre for cognitive neuroscience, said: ‘The biggest effects are on language and memory. The finding about memory impairment – the ability to encounter a pattern and remember it – really surprised us’.” 

Farah’s 2007 paper on “Socioeconomic gradients predict individual differences in neurocognitive abilities” relates: “Socioeconomic status (SES) is associated with childhood cognitive achievement. In previous research we found that this association shows neural specificity; specifically we found that groups of low and middle SES children differed disproportionately in perisylvian/language and prefrontal/executive abilities relative to other neurocognitive abilities… One hundred and fifty healthy, socioeconomically diverse first-graders were administered tasks tapping language, visuospatial skills, memory, working memory, cognitive control, and reward processing. SES explained over 30% of the variance in language, and a smaller but highly significant portion of the variance in most other systems.”  (See her website for more info on this and other papers:  http://www.psych.upenn.edu/~mfarah/ ) 

The Financial Times points specifically to the impact of stress: “Stress hormone levels tend to be higher in young children from poor families than in children growing up in middle-class and wealthy families, said Prof [Jack] Shonkoff. Excessive levels of these hormones disrupt the formation of synaptic connections between cells in the developing brain – and even affect its blood supply. ‘They literally disrupt the brain architecture,’ he said.” 

Shonkoff has an on-line article on the interface of neuroscience, psychology and social policy in the context of child development, which I definitely recommend taking a look at.  It includes a set of principles for understanding behavioral developmental and pediatrics, (1) Brains, skills and health are built over time; (2) Social, emotional and cognitive development are highly interrelated; (3) Brain architecture and human capabilities are built in a hierarchical, “bottom-up” sequence; (4) Brain plasticity and the ability to change behavior decrease over time; (5) Relationships are the “active ingredients” of early experience, and (6) The dynamics of stress in the developing child offer a promising model for thinking about causal mechanisms that mediate differences in learning, behavior and physical and mental health. 

The research by Farah and Shonkoff is important, but I would add one important caveat.  It is crucially important to not over-naturalize either poverty or the brain when thinking about this research.  SES glosses over the complex  political, economic and social practices that shape WHY some people are mired in poverty and others gather disproportionate wealth.  Similarly, it is not “the brain” that ends up poisoned—that brain is connected to a body, both those are embodied in a person who develops in a complex realm of social relations, meanings, and practices. 

In a concrete sense, the practices—the everyday life—of children growing up in poverty likely do not have the same rich scaffolding provided in other environments, coupled with the negative effects of stress.  Moreover, the effect of stress often hides what the real phenomenon is: the systematic disenfranchisement of people.  Disenfranchisement, the active denial of resources and the active pushing of negative forces, is more than stress.  A lot more. 

Krugman gets at some of this when he writes, “Living in or near poverty has always been a form of exile, of being cut off from the larger society. But the distance between the poor and the rest of us is much greater than it was 40 years ago, because most American incomes have risen in real terms while the official poverty line has not. To be poor in America today, even more than in the past, is to be an outcast in your own country.” 

He continues, “Growing up in poverty puts you at a disadvantage at every step.  I’d bracket those new studies on brain development in early childhood with a study from the National Center for Education Statistics, which tracked a group of students who were in eighth grade in 1988. The study found, roughly speaking, that in modern America parental status trumps ability: students who did very well on a standardized test but came from low-status families were slightly less likely to get through college than students who tested poorly but had well-off parents.  None of this is inevitable.” 

Krugman points to the importance of government initiatives and political will.  Shonkoff highlights connections between research, policy and program development.  I would add that efforts to stop disenfranchisement, the systematic denial of opportunities and the disproportionate thrust of our  worst social consequences onto those least able to fend for themselves, and efforts to help people help themselves, working with the resources and skills and desires we all have, are central to any attempt at stopping the ways we poison ourselves.  We humans create our inequality and our culture, and we need to think creatively how to engage our anthropological nature if we want to stop the poison.

10 thoughts on “Poverty Poisons the Brain

  1. This is an interesting subject. I wonder, though, if it may confuse cause and effect. It could be that people are poor are more likely to have depressive or anxiety disorders which lead them them to being poor. If you are depressed the chance that you are going to be poor is much more likely as you will be much less productive. But it probably ends up a vicious circle for the poor either way. If you are depressed you are more likely to do poorly financially which will make you more depressed.

    The other problem I have with this is that the “stress of poverty” is a little too vague. It seems like there are so many factors that would be hard to tease out. Some children who are rich may get picked on at school so they may also have high levels of stress. Though, I think more studies would need to be done to tease out the real impact of poverty.

    I think it would be good if schools could teach students ways to reduce their stress regardless of what their poverty level was. If stress has such a detrimental effect on cognitive functioning, then it could potentially pay big dividend in school performance.

  2. Daniel —

    I’m finding it interesting to check out the other blogs that are commenting on Krugman’s article. Many of them are vehemently critical: ‘Paul Krugman is a moron,’ ‘Only a PC liberal could come up with such nonsense,’ and the like. It seems to be a widespread insistence that, no, poverty is the effect of depression, lack of intelligence, being unhealthy mentally, etc., and a real refusal to consider the possibility that environment might have these profound effects on people. In fact, most of the research on which these studies are based is pretty sound (as I’m sure Daniel would agree), and the indications are that poverty has profound effects on IQ scores, likelihood of depression, and likelihood of all sorts of negative outputs.

    The complexity of social causes is no reason to discount them. Absolutely, mental illness or other psychological troubles may be ‘inherited,’ but there are many mechanisms that might explain this other than an innate, biological (read ‘genetic’) one. Property, titles of nobility, religious affiliation and political persuasion are also patterned from generation to generation and demonstrate a pattern of inheritance. You’d be hard pressed to find any reputable scientists looking for a gene for these sorts of things.

    But I agree with Michael that the sociological-level data can’t be easily tied directly to the psychological-level outcome; there might be many layers in between that would intervene, creating resilience, for example, in certain people who grow up poor or, inversely, placing people in socio-economic positions under stress that makes them as likely to have depression as someone born in much less secure socio-economic status. Unfortunately, one of the ways to study this is to look at the relation between parents’ and children’s likelihood of both suffering depression or stress-related illness or the like, and then the data is taken by some observers to show biological inheritance when, in fact, it’s a great indication of the environment that children are subjected to within the household.

  3. “But I agree with Michael that the sociological-level data can’t be easily tied directly to the psychological-level outcome; there might be many layers in between that would intervene, creating resilience, for example, in certain people who grow up poor or, inversely, placing people in socio-economic positions under stress that makes them as likely to have depression as someone born in much less secure socio-economic status.”

    I think what would be needed is to define what aspects of poverty might increase a person’s stress. You can be fairly poor material wise, but lead an unstressful lifestyle. If I got rid of my television, computer and telephone I think my own lifestyle would actually be less stressful. However, there are certain aspects of poverty which might lead to increased stress. Obviously if you don’t have enough money for food or are uninsured for healthcare you are going to be more stressful.

    There is some indication that nutrition can have a substantial impact on cognitive functioning as well. Omega 3 fatty acids have been shown to increase brain volume in areas like the hippocampus. Nutritional deficiencies have also been tied to lower IQ levels. So that is another aspect to poverty that could potentially be addressed fairly cheaply.

    If elevated stress hormones are the cause of many of these problems then it might be possible, in the future, to give at risk kids drugs which supressed the stress response (like cortisol reducing drugs). But that is a totally different ethical debate at how to best attack this problem.

  4. “Bad Grades? Faulty Memory Could Be To Blame” reads today’s headline, with the following opening: “Defects in working memory — the brain’s temporary storage bin — may explain why one child cannot read her history book and another gets lost in algebra, new research suggests. As many as 10 percent of school age children may suffer from poor working memory, British researchers said in a report last week, yet the problem remains rarely identified.”

    Poverty impacts memory and language, as Martha Farah showed, and that then impacts the ability to get good grades. Grading is a sociocultural system, which reflects one way we rank people in society. And rather than talking about the system, we generally focus on the “individual” who fails at school, thus providing a convenient ideology for a much more systemic problem. As today’s article relates, “Many children with poor working memory are considered lazy or dim. But Alloway said with early identification and memory training, many of these underachievers can improve.”

    Here’s the link: http://news.yahoo.com/s/nm/20080302/sc_nm/memory_learning_dc;_ylt=Au_0zmePpX4YzuAftbZXBZKs0NUE

    And if you’re interested in how this sort of dynamic might play out based on further research, a great way to start is to combine two books: Gustafson & Magnusson’s Female Life Careers: A Pattern Approach, which uses longitudinal data to document the replication of inequality and social class from childhood, and MacLeod’s Ain’t No Making It: Aspirations and Attainment in a Low-Income Neighborhood, which shows the impact of social structures and lived experience on how and why poverty persists

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