Poverty stresses kids’ brains

Childhood poverty creates chronic stress which impairs working memory, research finds.

The longer 17-year-olds had lived in poverty, the higher their stress hormones and the lower their working memory scores, researchers found.

Those who spent their entire childhood in poverty scored about 20 percent lower on working memory than those who were never poor, (Cornell Professor Gary) Evans said.

I see a chicken-egg issue:  Is below-average memory the result of living in poverty or the result of being the child of a parent who’s chronically poor because of below-average memory.

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  1. There are more chickens and more eggs here.

    1) Making bad choices causes bad outcomes (which cause additional stress).

    2) Making bad choices causes poverty.

    3) Being poor causes stress.

    4) Being poor by directly precludes some good choices. (i.e. wealth allows superior options.)

    5) Observing their parents making bad choices predisposes children to make similar bad choices.

    6) Stress impairs memory, causing more poor choices.

    7) Stress affects judgement, causing more poor choices.

    8) Low intelligence, roughly 50% of which is inheritable, also predisposes to poor choices.

    I’ve probably missed a few, but it’s a whole nexus of things. There’s also quite a bit about the motivation for good choices, what happens socially to a kid who makes better choices than their parents and friends, and so on.

  2. Andromeda says:
  3. It can’t be a chicken-egg issue unless you can show causality in even one direction, never mind both. Being raised in a single-family home or one with substance abuse problems can cause both poverty and stress.

  4. The tendency to blame poverty on inherent genetic predispositions has been gaining ground recently–and that’s too bad. The claim that low intelligence is “50% inheritable” rests on very slender evidence, indeed.

  5. Claus –

    I did not “blame poverty” on genetics. I did say that low intelligence is inheritable — undeniable, or some koala bears and flamingos would be physicists — and that it predisposes people to poor choices. (Hopefully you will allow that second half by inspection, or must I define intelligence as “the ability to anticipate outcomes and select the actions that lead to the better ones” to get that point? And making bad choices leads to poverty, also undeniable.

    Regarding the 50% figure, it was from 1980s twin studies, and no doubt there is newer evidence out there. Show me evidence that the correct number is 37% or 71% and I will be quite happy to hear it. I prefer “slender” evidence to none at all.

    (Pause for a quick google.)

    Oops – you are right – the current scientifically accepted figure is closer to 70%. See the NY Times for the results of a 1990 study.

    Then there’s this study that popped up last month in Technology Review –

    According to the findings, about 85 percent of the variation in white matter in the parietal lobe, which is involved in mathematics, logic, and visual-spatial skills, can be attributed to genetics. But only about 45 percent of the variation in the temporal lobe, which plays a central role in learning and memory, appears to be inherited.

    So heritability of brain function varies by what type of intelligence we are talking about, of course. I believe the current scientific formulation of the statement is that “intelligence is unlikely to be less than 40% or greater than 80% inherited.” So 50% is being kind.

  6. Dal,

    Are you sure its size? It may have more to do with how you use it 🙂

  7. pm – I never mentioned size. The more important component of brain function is interconnectedness, the density of formation of dendrites. (This is why women, with smaller brains than men on average, have roughly the same intelligence as men – they also have denser neural interconnection relative to men.)

    But, it’s not me making any claims, I’m just saying what the current scientific consensus is, which claus was implying is not well founded. Unfortunately for claus’s case, there is zero data and no current scientific theory available to imply that heritability is significantly less than 50%.

    Now that I’ve replied deadpan, let me give you back a smiley – 😉


    It was either that or talk about how mine is bigger than yours…. 😉

  8. Margo/Mom says:

    Andromeda’s link is interesting. In short, it doesn’t challenge the study as much as the reporting of it and the bandwagons that people are all too ready to jump onto. It points out that it is important to ask questions with regard to how much difference is there, in what, and what does that mean to us.

    I also looked at the 1990 twin study. One comment was that if family members (beyond just the identical twins) were included, the heritability of intelligence tends to drop. Which says that there is perhaps a greater level of individualization to intelligence than we would like to admit.

    But this study does not deal with heritable factors, it deals with environmental factors. What is interesting, again, is what bandwagons people choose to jump onto. One might accept rather easily that heritability falls outside of the realm of the schoolroom to impact. But when we come to environment–why are all the same folks standing up to say again–see there’s not much we can do, the kids are already limited before the get to us.

    What other profession does that? Do dentists insist that there’s nothing they can do about brushing habits or candy eating behavior? Or do they take these things into account and look for ways to have an impact–even though it’s “the parent’s responsibility?” Do doctors recoil from providing care for inherited conditions, or do they still seek to not only understand causes and preventions, but ways in which to improve the quality of life of their patients who suffer from such conditions? I am sure to get an earful in short order explaining why teachers are like none of these–they work longer for less pay and less respect, etc. Please restrain. I am not about to defend the salary scale of teachers, even though it is higher than many workers of equivalent education and expertise: social workers, some health care workers, etc.

    The point that I am trying to get to is that by using every shard of research that crops up in support of the notion that we cannot do better than we are already doing (unless perhaps there is more money, or more time, or fewer students, or more support, or fewer chronic disrupters, etc.) because of some flaw in our students (or their parents or community), leads us to overlook things that the same research might point out that we could be doing–that might not even require more resources and all. If the research has traced a path from poverty to stress to diminished short-term memory, mightn’t we more profitably be asking questions about how much stress-load is being added by their time in school? If we were to pay attention to school climate, might we find that many students do not see their schools (particularly from middle school on upward) as places of safety, welcome and nurture? Can schools become places of greater predictability, structure and stability? Mighten’t this result in lower stress loads?

    pm was right about size–it’s more about how you use it, with many things. Perhaps we need to be thinking about how we use research. Does it serve to offer up new reasons to accept huge differences in learning across SES levels–or does it open our eyes to things that we might be paying better attention to in order to make existing schools more productive places for the kids we actually have there?

  9. Isn’t childhood poverty sort of relative? If everyone around you has about the same income level, are you really poor?

  10. “Experiential factors can include things like having fewer trips to museums, having fewer toys, having parents who don’t have as much time or energy to engage with them intellectually — to read to them or talk to them.”

    I don’t think Lincoln went to the museum very often. I’m not so sure that toys and field trips make you smarter. And parents who don’t have time (because they’re working 4-5 jobs?) can cut across plenty of income levels.

  11. Dal,

    I meant size of intelligence and not size of any organ 🙂

  12. Parent2 says:

    ” If everyone around you has about the same income level, are you really poor?”

    You’re poor if you can watch the t.v. and see people who have more than you. Children often cite musicians, athletes, movie stars as role models; if you can see them on t.v., they’re part of your mental community.

  13. So one kid sees Donald Trump on TV and gets all bent out of shape. Another might see the same thing and think “I want to do/be/have that”. Are we never supposed to see anyone or anything that’s not just like us?

  14. No. That’s not my point, and you’re reducing it to nonsense.

    Turn it around. What we see frequently, particularly the people with whom we identify, become our yardstick to measure what’s normal. For example, the rap stars dress in a certain way, and behave in a certain way. They sing about a decadent, misogynistic lifestyle, and they are widely thought to be rich. Hundreds of thousands of students copy their dress, behavior, and language. The manufactured consumerist culture available on t.v., radio, the internet, in movies, influences our perception of what’s normal, and thus desirable.

    Homeschooled children who don’t have t.v., and don’t listen to popular music, might be less stressed than “normal” children. That would be an interesting study.

  15. Margo/Mom says:

    The study was not concerned with children’s perceptions of relative prosperity or poverty–or how smart or dull their parents might be. It concerned levels of stress–which were demonstrably different in kids growing up in poverty than otherwise (as a group). Further, kids with higher stress levels demonstrated less efficient short term memory. It has nothing to do with singing songs, hearing about decadence, or whether rap stars have higher level of stress than other people.

  16. Andromeda’s link leads to a blog post which references an Economist article about the same study. The end of the article points out that poverty may be associated with stress, but that the stress may have many causes. (http://www.economist.com/science/displaystory.cfm?story_id=13403177)

    “Dr Evans’s and Dr Schamberg’s study does not examine the nature of the stress that the children of the poor are exposed to, but it is now well established that poor adults live stressful lives, and not just for the obvious reason that poverty brings uncertainty about the future. The main reason poor people are stressed is that they are at the bottom of the social heap as well as the financial one.

    Sir Michael Marmot, of University College London, and his intellectual successors have shown repeatedly that people at the bottom of social hierarchies experience much more stress in their daily lives than those at the top—and suffer the consequences in their health. Even quite young children are socially sensitive beings and aware of such things.”

    Knowing that you have very little, and that others have much more, causes stress. “Pecking order” is a term rooted in chickens. Being the bottom of the social hierarchy causes stress.

  17. Margo/Mom says:


    I beg to differ, but poverty is stressful whether one knows that there are others ahead of you in line or not. Knowing that your next dollar is still a week away and the refrigerator is empty is stressful–whether one believes that everyone has the same problem of not. Moving repeatedly–either due to eviction from not having the bucks to pay the rent, or because the landlord refuses to spray for bugs or to go where the jobs are is stressful. It is more stressful to take clothes to the laundrymat, in a taxi, or begging a ride with a neighbor who has a car, or hauling clothes on the bus, than it is to toss in a load every night in the laundry room.

    If you want to give it a try, pledge to give up your car and washing machine for the next month. If you really want to up the ante, find out what the food stamp budget is for your family size in your state and commit to this for your food budget for the next month.

  18. Maybe, but one’s spot in the social hierarchy still has consequences. Both factors can be stressors.

    We live in an affluent suburban school district. I have heard complaints from middle-class parents about the competition between students (particularly girls). Who has the best clothes, vacation plans, cell phone, car, etc. According to these mothers, it makes for a very stressful setting. There is no material need for any of these children. The closest a family gets is needing to mind their budget. And yet, the mothers perceive stress based on material possessions.

    It would be interesting to see if this effect would scale with income, or if it’s more a question of meeting basic needs, i.e., after a certain point the effect disappears. And, again, does electronic media play a role in perceptions.

  19. Margo/Mom says:


    As I understand it, they were measuring actual physical indicators of stress on a scale that combined things like blood pressure, etc. The compared low-income (I am guessing based on something like free and reduced price lunch eligibility–the usual proxy, which tops out at something like 150% of the federal poverty level, if memory serves) with non-low-income kids. It would generally be confirmed by overall health conditions over time. Health outcomes go up with income level, with a bit of levelling out at the lowest end families, where kids generally qualify for medicaid.