Friday, April 17, 2009

poverty, stress, memory

An article in the Economist reports on a study that seems to show that poverty causes stress in children and this erodes their working memory:

"THAT the children of the poor underachieve in later life, and thus remain poor themselves, is one of the enduring problems of society. Sociologists have studied and described it. Socialists have tried to abolish it by dictatorship and central planning. Liberals have preferred democracy and opportunity. But nobody has truly understood what causes it. Until, perhaps, now.
...
To measure the amount of stress an individual had suffered over the course of his life, the two researchers used an index known as allostatic load. This is a combination of the values of six variables: diastolic and systolic blood pressure; the concentrations of three stress-related hormones; and the body-mass index, a measure of obesity. For all six, a higher value indicates a more stressful life; and for all six, the values were higher, on average, in poor children than in those who were middle class. Moreover, because Dr Evans’s wider study had followed the participants from birth, the two researchers were able to estimate what proportion of each child’s life had been spent in poverty. That more precise figure, too, was correlated with the allostatic load.

The capacity of a 17-year-old’s working memory was also correlated with allostatic load. Those who had spent their whole lives in poverty could hold an average of 8.5 items in their memory at any time. Those brought up in a middle-class family could manage 9.4, and those whose economic and social experiences had been mixed were in the middle.

These two correlations do not by themselves prove that chronic stress damages the memory, but Dr Evans and Dr Schamberg then applied a statistical technique called hierarchical regression to the results. They were able to use this to remove the effect of allostatic load on the relationship between poverty and memory discovered originally by Dr Farah. When they did so, that relationship disappeared. In other words, the diminution of memory in the poorer members of their study was entirely explained by stress, rather than by any more general aspect of poverty.

To confirm this result, the researchers also looked at characteristics such as each participant’s birthweight, his mother’s age when she gave birth, the mother’s level of education and her marital status, all of which differ, on average, between the poor and the middle classes. None of these characteristics had any effect. Nor did a mother’s own stress levels.

That stress, and stress alone, is responsible for damaging the working memories of poor children thus looks like a strong hypothesis."

awful thought, right? maybe I'm not understanding how the statistical techniques work, but I might also want to look at whether the quality of the schools the kids went to had any impact.

Just for context: "Children are considered to be living in poverty if their family income, before taxes, falls below the poverty thresholds set by the federal government for families of different sizes....In 2005, the poverty threshold for a single parent and two children was $15,735; for a married couple with two children the poverty threshold was $19,806 ... In 2005 (the latest year available), the highest rates of child poverty occurred in three of the five boroughs of NYC: Bronx (39.4%), Kings (which includes Brooklyn) (30.9%) and New York (29.9%)."

If you don't live in NYC, please understand that the conditions kids live in here are even more dire than in other parts of the country, simply because $15,735 doesn't go nearly as far here.

(info from the NY State Kids Well-Being Clearinghouse)

19 comments:

Anonymous said...

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Will said...

I think I fundamentally disagree with this work. My own parents were poorly educated having grown up in postwar london and so their parents had limited access to illectually stimulating experiences. This they then perpetuated during the childhoods of their children and hence we had not experienced alot of things my middleclass friends had.

At age 14 I could not ask my parents for help with my homework because it was far beyond anything they had learned (or had forgot long ago). My wife, on the other hand, had parents who set out to change the circumstances of their children because of the enviroment they grew up in, communist Bulgaria. Access to culture was the norm for all and as a result she has a much wider appreciation of these things.

I am a firm believer of the more you know, the more you can know school of thought and hence a greater immersion in intellectual activities leads to a greater capacity for learning and IQ.

Anonymous said...

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Anonymous said...

Like you I saw this paper cited in the popular press, but I think the term stress is more complicated. Many people live complicated stressful lives - look at the kids who are pushed to excel in academics. In the Far East, many school kids get up early to get to school and after school, go to another 'after school school' where they drill and prep for the all important national standardized exams which determine future school placement, and this cycle goes on all the way until 16 or 18. Some kids can't take the pressure and have even committed suicide after failing a big exam.

Another explanation of what the researchers found is that the kids who have had hard lives had to give up a bigger part of their early lives to scrambling around to find food and shelter. By devoting more of their day to sorting out the sort of issues which the better off kids' parents would take care (e.g. what is their to eat, where do I sleep, will I stay warm, will I have anyone who cares or show affection or friendship) they lose out on the chance to develop other faculties.

I think this observation may also explain why some very poor kids could nonetheless succeed because though their families couldn't provide much material support, they could compensate by providing emotional support. It is the rare kid who has meager material or emotional support who succeeds. Usually in the most hard luck tale, at some point, some adult sees the kid has great promise and gives a helping hand - maybe just a little bit of food or a kind word, but for some kids that means a lot emotionally and helps them weather their stormy lives.

anjiaoshi said...

I'm not finding it right now, but a few years ago, I read a report that inner-city children living in poverty often showed signs of post-traumatic stress disorder.

Anonymous said...

Wrong.

2 words:

Bobby Fischer

ATH2044 said...

Elizabeth:
"maybe I'm not understanding how the statistical techniques work, but I might also want to look at whether the quality of the schools the kids went to had any impact."
The statistical technique (hierarchical regression) used is explained here:
http://en.wikipedia.org/wiki/Hierarchical_linear_modeling
My impression would be that if "the quality of the schools the kids went to had any impact" on their stress (as measured in the the article in the Economist) then it would have an impact on the outcomes (i.e. "diminution of memory in the poorer members") as well.
Hierarchical linear modeling is appropriate for use with nested data. & according to this article, http://en.wikipedia.org/wiki/Multilevel_model, it seems to be particularly applicable to school systems.

Will said... "I think I fundamentally disagree with this work."
Then gave a bunch of anecdotal threads that don't seem to make the case since the premise is:
"That stress, and stress alone, is responsible for damaging the working memories of poor children..."
My question would be did any of the conditions you mention cause a measurable increase in the specific stress factors cited in the article in the Economist?
However, I concur with you that "...the more you know, the more you can know..." It's just not the relevant issue. (The hierarchical regression technique cited above supposedly corrected for such factors.)

anjiaoshi said... "I'm not finding it right now..."
I recall reading about that (PTSD Inner City) also. This article http://www.giftfromwithin.org/html/parson.html seems to be something like what you're looking for.

Anonymous said...

Most of the "stress factors" they measured could also have been caused by an overabundance of McDonald's in the diet.

I suspect that the diet most poor people have is far more responsible for all physical limitations on thinking than the stress on the child.

If they did this same test, breaking the poor children up by cultural background, I suspect that you would find this report to be much more true of poor whites & poor blacks than poor asians, for instance. Poor asians live off of rice - poor whites & blacks live off McDonalds.

Essentially, if someone *tries* to provide for their kids in a responsible fashion, I have trouble believing that the kids suffer nearly so much. Too often I see poor kids who don't eat at home & eat at McDonalds; they share beds with their brothers, but wear Nikes; Mom & Dad can find money for cigarettes and alcohol, but can't find the time to look for a job. My favorite Texas-centric polling method regarding the lack of responsibility among the poor is to cruise through a Mobile Home Park and count the number of expensive trucks & nice cars, typically with thousands invested to make the car "bounce" or to stereo upgrades.

Anonymous said...

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anjiaoshi said...

Wrong. 2 words: Bobby FischerThe plural of "anecdote" is not "data."


Most of the "stress factors" they measured could also have been caused by an overabundance of McDonald's in the diet.Please google the phrase "food desert."

anjiaoshi said...

Wow. Why did the formatting on that come out so screwed up?

Michael Goeller said...

I just read an article titled "Why Don't Students Like School?" in American Educator that may make some useful connections for you. If you can make the case that chess is a powerful way of improving working memory (which makes sense), that supports teaching chess in schools where students are likely to be stressed by socio-economic factors.

Anonymous said...

"Too often I see poor kids who don't eat at home & eat at McDonalds; they share beds with their brothers, but wear Nikes; Mom & Dad can find money for cigarettes and alcohol, but can't find the time to look for a job. My favorite Texas-centric polling method regarding the lack of responsibility among the poor is to cruise through a Mobile Home Park and count the number of expensive trucks & nice cars, typically with thousands invested to make the car "bounce" or to stereo upgrades."

I'm surprised your comment didn't get deleted already. Those are the people that liberals want us to feel bad for and why Obama got voted in. Lets give them Joe the Plumber's money since they are having such a hard time finding jobs.

Anonymous said...

Aoshi - I find the "food desert" argument more compelling IF the grocery stores truly do not exist in certain areas. Where I live, there is a substantial amount of poverty and the focus is on the low end fast food chains but there are still grocery stores present.
The third argument for 'lack of access' to healthy foods was mental attitude or poor food knowledge, and I don't consider this a valid excuse - much like using ignorance of the law as a defense.

an ordinary chessplayer said...

Those who had spent their whole lives in poverty could hold an average of 8.5 items in their memory at any time. Those brought up in a middle-class family could manage 9.4 ...Even if their conclusion is correct, the difference is not decisive, at least for USA-defined poor. Thus there will always be plenty of anecdotes to muddy the waters. Let's see this theory tested on a global sample, where poverty is defined as an income of hundreds of dollars per year. Now that's stress!

Elizabeth: I hear you about the schools issue. It doesn't look like they examined that, but since worse-better schools will not track more-less stress or lower-higher income precisely, I think the statistical techniques could find the answer. Provided they have that data point for their analysis.

Poor asians live off of rice ... McDonald's is working hard on this problem.

an ordinary chessplayer said...

anjiaoshi wrote: Wow. Why did the formatting on that come out so screwed up?

In the preview screen it looks normal. But the published version is stripping out the newlines after the html tag.

an ordinary chessplayer said...

Looks like that worked, I put a space after the closing tag.

no space after2 newlines before, 2 after

trailing space

2 newlines before, 2 after

In the preview, both samples have the same line breaks. Let's see what the published verion does.

ATH2044 said...

"I'm surprised your comment didn't get deleted already."
That's nothing but a cheap shot since you produce no evidence that such comments are ever deleted. In fact somewhere in the not too distant past, Ms. Vicary identified her criteria for deletion to be something along the lines of personally insulting (to her) &/or grossly off topic.
I'll spare you my comments about your Limbaughistic use of the word "liberals" & point out for your general enlightenment that:
A.) "Joe the Plumber" (aka Samuel Joseph Wurzelbacher) is not a licensed plumber.
B.) Does not now nor did he ever own a business worth more than $250,000 nor earn a salary above $250,000 per year. (This was his argument against "raising taxes on all us 'small business owners' making a little more than $250,000 per year cited above.")
& of course
C.) His name is Samuel Joseph Wurzelbacher, which makes him Sam (not Joe) the New Poster Child for Right Wing Lies (NOT the plumber).
I gotta go play some chess.

an ordinary chessplayer said...

My favorite Texas-centric polling method regarding the lack of responsibility among the poor is to cruise through a Mobile Home Park and count the number of expensive trucks & nice cars, typically with thousands invested to make the car "bounce" or to stereo upgrades."As I see it, the problem is not that, because they live in a poor home and have a tricked-out car, they therefore have misplaced priorities. The problem is that you are going out of your way to judge them. (Unless of course you live there, in which case you are still judging "them" but not going out of your way.)

When I walk through the nice neighborhood and see the nice cars in the driveways, at first it seems so great. But then I pause to reflect on the fact that much of it was bought on credit (on time as they used to say). Could it be they are doing the same as the trailer-park residents, but with their car *and* their home?

Don't know. Anyway, you're welcome to cruise past my run-down efficiency apartment and sneer at my 12-year old beater parked out front. When I waste *my* money, it's on something you won't see, such as another computer that I don't need. Or a chess tournament.

In the meantime, I have a job, a savings account, a modest 401(k), and an American dream. I'm pleased to live in a country where people are free to defy difficult circumstances with their ride, or their clothes, or whatever. Where they can say, "Yeah, I ain't got much, but I'm still proud." Instead of cruising, you might actually get out and say hi. I bet if you say something nice about their car, they'll offer you a beer.