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ANNOUNCER: This is a presentation by Human Development Outreach and Extension at Cornell University.
GARY EVANS: Well, let me tell you what I'm going to do. I'm going to give you an overview of what I call the environment of childhood poverty. And what I mean by that are what are some of the social and physical characteristics of the settings that low-income children grow up in? And the reason why I'm doing that is because it's crystal clear that poverty is bad for child development. The amount of evidence for that I would characterize as overwhelming. But what's not so obvious is why is poverty bad for children? So what I'm particularly interested in is trying to answer the question why is poverty bad for children's development?
The conclusion that I'm going to reach is that the reason why-- one of the reasons, not the only reason, but one of the reasons why poverty is bad for children's development is because of a confluence of risk factors, a coming together, a convergence of multiple risk factors.
So let me start off by just giving you some background information, some of which I think you're familiar with, or some of you are familiar with, having to do with sort of who is poor, how many people are poor, what do we mean by poverty? These are international data and sadly, the United States is leading the pack in terms of the poverty rate for children. And this, as you can see, is in economically developed countries. We're quite a bit higher than most other economically developed countries.
This is what poverty meant last year in the United States. Poverty is defined in the US by something called an income to needs ratio. I won't bore you with the origins of that, but it's a rather arbitrary, not well-defended definition of poverty. But nonetheless, it's basically a per capita income index. One of the problems that you can immediately understand is it's the same throughout the United States. So if you live in Manhattan or if you live in Ithaca, how poverty is calculated is in the same way.
One of the things that many people are not aware of, at least in the public-- I suspect many of you are-- is that where an awful lot of poverty is in the US, sadly, is in families with younger children. So this is age group down here. So this is where there is a lot of poverty. This also represents very interesting data for a successful social experiment. When people say, well, we can't do anything about poverty, that's patently false because elderly-- before Social Security, what this graph looked like was the perfect U. So very old people were also at very high rates of poverty. But after the implementation of Social Security, that went away. So there's good evidence that we could reduce poverty if we have the will, both political and ethical and moral to do so.
Another thing about poverty is most of the media attention is on urban, inner city people of color. Most people who are poor in the United States are white. They're not people of color. And per capita, there's much more poverty in rural areas. The severity of the poverty in rural areas, how deep the poverty is, and how long it lasts is much worse. If you look at the fastest growing areas of poverty in the United States, which, as we all know is taking off right now, much faster growth in rural areas. So there's a little bit of a misfit between kind of the public perception of poverty and the reality on the ground, so to speak.
There's lots and lots of evidence that poverty is bad. Let me just kind of review some of that, and then I'm going to turn to this issue about why is poverty bad. Poverty is bad for your health. So as you can see in this example, compared to babies born to mothers with 16 more years of schooling versus less than 12, essentially a high school dropout, you can see there's a rather dramatic impact on infant mortality. So something as basic as does a baby live is related to income and education.
Health problems in children-- so going from the lowest SES-- SES stands for socioeconomic status, which is a composite index of income, education, and occupation. And as you can see here, there's a pretty clear gradient in many very common childhood diseases. For example, the number one reason why children miss school-- and you might think about poverty, school achievement and think about what I'm showing you right here. Kids aren't in school. That's part of the reason why they're not doing as well.
Lots of different ways you can look at this on different scales. This is urban poverty, as you can see, looking at different parts of New York City. It's just a composite. The New York City Department of Health has a very strong interest in what are called health inequalities. Why do we get these unequal distributions of income and what can we do about that to sort of get rid of that gradient? So this is a major initiative of the current Commissioner of Health in New York City. And it's just showing you the same kind of thing that I showed you a second ago, that there is this pretty clear link between income or socioeconomic status and health.
You can also look at mental health. This is a national study starting at age 12 and then every two years going out in time. So this is a 12-year-old, 14, 16, 18, and looking at, as you can see, high, medium, and low SES and a very pronounced increase in aggression. This is a pretty standard index. For those of you who are familiar with it, it comes from something called the Achenbach. It's a very standardized measure of sort of mental health in a nonclinical sample. So this is sort of like everyday typical variability in aggression. We're not talking about extreme pathology. We're talking about the amount of variability you'd see in typical kids.
Similar thing for withdrawal. So as children getting older and they're poor, not only are they getting more aggressive but they're also withdrawing more and more.
SPEAKER 1: So the time is age.
GARY EVANS: Time is age-- 12, 14, 16, 18. And this is a national sample of several thousand children.
Thought problems-- so again, just trying to give you a feeling of some of the links between income or SES and developmental outcomes that you all are very concerned about and know are important.
Aggression, physical aggression, in boys and girls-- down here, we're going from low SES to higher SES. And cognitive development-- this is a particularly damning slide of American society. Let me explain why.
If you look closely at what this is showing you, it's showing you something that's very alarming. First of all, it's saying that when kids hit kindergarten, as a function of their income quartile, here's the low-- whoops. Here's the low. Here's the high. They're already behind, right? So we're already behind when we start kindergarten. The damning part is look what happens over time. The longer you're in school, the farther behind you get. That's a terrible situation.
Of course, one of the goals of No Child Left Behind was to try to do something about reducing this income achievement gap. Now, it's not fair to judge that legislation and that initiative on trying to reduce this achievement gap because it's such a difficult, complicated problem. But nonetheless, that was one of the-- one of the reasons. There were many, but that was one of the reasons for the No Child Left Behind legislation was to try to reduce this income achievement gap.
I mentioned earlier that there might be some interesting connections between health and performance in school and socioeconomic status or income. So low-income children are more likely to have asthma. They're more likely to miss school, and of course, if you're not in school, it's harder to learn and to achieve. And indeed, there is a pretty clear link, as you can see here, between family income and absences due to illness.
And one of the-- so lots and lots of data, lots of evidence. I just showed you a little tip of the iceberg about links between children's income and outcomes that are important-- health, cognitive development, socioemotional development, wide range of things.
So as I said, one of the questions that that, of course, leads us to is why? How come there is this relationship between childhood income levels and class and health and cognitive development, and socioemotional development? Well, one of the reasons is probably related to access to health care and health related behaviors. Again, the conclusion, the punchline is that, I think, it's all of these things. And in fact, what I think it is in particular is the confluence of these different things. So the same family that may have some difficulties with health insurance is also the same family that's more likely to have an asthmatic kid, who's more likely to miss school, who's more likely to be facing a lot more conflict and turmoil. So a lot of these things are going together.
So right-- even before birth, in America, if you're poor, you start off with some risk, as you can see here. So you're more likely to be low birth weight, premature, and this is a very shocking statistic, in terms of the adequacy of prenatal care.
We don't have too much malnutrition in the United States, but we do have what's called under-nutrition. We also have something called food insecurity, which I know FNP is a program that's trying to address some of that. And not surprisingly, there is a link between concerns and worries, food insecurity. What this means if you're not familiar with it, it's usually a mom, let's say, although, sometimes it's both parents, the extent to which the household is concerned and worried about whether they can adequately feed their children. So ask things about like do you have to trade off buying food versus paying a utility bill? That would be an example of some of the kinds of ways people try to get at this. Some of you, I think, know Chris Olson and some of her work and Carol Devine. They're both using food insecurity as one of their important concepts.
Children receiving vaccinations-- this has not changed very much since this, a little bit but not very much. So children who are below the poverty line are less likely to get vaccinated.
Coming home from the hospital using an infant car seat, buckled into the safety seat, do you have a Poison Control sticker on your phone? And you can see there's this gradient again. So as you go from low income to higher income, there's a pretty dramatic increase. Although these numbers are not what we'd like them to be, but they're certainly a lot higher than they are down at the bottom, right? So not quite a doubling, but it's a lot. It's a big change.
And we know that adolescents engage in risk behaviors related to health-- illegal drug use, unsupervised alcohol use, cigarette smoking, et cetera. Strong gradient in terms of income. So as you can see here, by age 12-- this is a composite, engaging in one or more of these behaviors down here. So engaging in one or more of these, you essentially cut it in half from less than $15,000 to greater than $50,000.
So as I said, I'm interested in this question why is poverty bad for children? I think it has a lot to do with stress, and I think it has a lot to do with stress from some of these different factors that I've alluded to.
This is a Gallup poll, a representative sample of the United States. And as you can see, what they're looking at is this is adults, perceived stress. This is a standardized scale. It's quite a good scale, actually. And it's very interesting. It's not just, by the way, that the poor have more stress than other people. You'll also notice that middle class people have more stress than rich people. So is Donald Trump happier than you are? Yes, he is.
SPEAKER 2: And that's percentiles on the bottom there? Or do we need to go back to just the x there?
GARY EVANS: These are--
SPEAKER 2: Below the fifth percentile?
GARY EVANS: That's a good question. I have a feeling it's actually income.
SPEAKER 2: Income.
GARY EVANS: I think it's income. So I think this is greater than $50,000. I don't think-- yeah, this is $50,000. This is $5,000.
So one of the reasons that, I think, poor children are more likely to have health problems of various kinds is they're confronted by a lot of psychosocial settings that are potentially problematic for children's development.
So what I'm going to do now is I'm going to show you kind of an overview of some of the psychosocial characteristics that are linked to income and class in the US. I have a few data from other countries just to give you a feel that this is not just an American phenomenon but I'm focusing on the US. And then, I'm going to show you sort of the analogous thing from physical stressors or physical settings. So start with psychosocial, in this case, as you can see, talking about family separation and divorce.
And we'll move through social into physical. And then, I'm going to actually show you some data from an ongoing study in upstate New York looking at rural low income families that's trying to test out this hypothesis, that maybe one of the reasons why poverty is bad is because this confluence of risk.
These are data that most Americans do not know, which is that there's a very strong gradient between income and divorce. And notice that it's controlling for household size. So it's not simply a factor of single parenthood. You see a very similar thing in Britain. I have to warn you that in Britain they flip over. So this is the professionals and this is the poor. So the British slides are like we're driving on the wrong side of the road, OK? Yeah.
So if you're poor in Britain, you get married sooner, you get divorced faster and more often. You're a lot less involved in your child's school. Low-income parents feel intimidated, threatened, uncomfortable in schools, I think, despite very good sincere efforts by schools to make them feel welcome. Partly, I think, because of them, themselves, maybe not having had good educational experiences, being worried about their children, maybe being embarrassed by their children's performance. It's a tough one to try to overcome, but it's a very pervasive phenomenon.
Low income parents, in general, are not very active and involved in schools and it has a lot to do with how they feel about it. Not necessarily an accurate perception. That's not what I'm claiming. I'm just saying that clearly, there is this lack of involvement that all of us would like to see more of. And of course, it's very frustrating for teachers. What teachers report is they see the parents of the kids who are doing really well, and they don't see the parents, in general, of the kids that are struggling, which, of course, is very frustrating from their perspective.
And this is a fascinating study. I wish I had done this study. This is a study by a woman named Betty Hart, who is, I think, now emeritus, a developmental psychologist from Kansas. And one of the things that's interesting about this study is-- I'll go on a little tangent here because I think you'll find this kind of fascinating.
This study was not designed to look at income or education. That was not the purpose of the study. The purpose of the study was to look at the relationship between parents' language and speech, and children's development. Betty Hart is a cognitive developmental psychologist, and she is particularly interested in language development and the role of speech and reading and things of that sort.
So what they were interested in was trying to get a much more ecological kind of realistic view of that. So what they did was, starting at six months of age and then every six months-- or three months-- three months up until age three-- So every three months they went to families and spent several hours in their homes recording all of their child/parent interactions, which is just an amazing logistical undertaking if you stop and think about that for a second, what they were actually doing. They're going to the homes, spending a couple hours there for three years, more or less, every three months.
One of their graduate students noticed that there were huge differences in the behavior of the parents in relationship to their background. So they started to explore this. They actually wound up writing a book about it. It's called Meaningful Differences. And as you can see here, these are dramatic. These are not small effects. In psychology, we talk about effect sizes. These are off the chart.
So this is the number of words, just literally how many words are being spoken to. So this is people, parents on welfare, speaking to their child. Another thing that's also interesting is not only the difference in the magnitude, this one's pretty flat. So the parents here are talking to a very young child and a toddler in almost the same way. And this one, it's not perfect, but you'll notice that there's a little bit of a upward slope and here, too, not quite as dramatic.
So we call that scaffolding, right? So these parents and these parents sort of figure out, well, the child's getting older. I need to change the way I interact with my child. This is literally just speaking. The book is full of graphs about what type of words, how responsive. Did the parent respond to the child or did they always initiate?
It's an absolutely fascinating book. It's called Meaningful Differences. Hart, H-A-R-T. Elizabeth, Betty Hart, is the author.
And this is an old study by Jerome Kagan, who is a very well-known, respected developmental psychologist. And this is a study-- Kagan is an infancy researcher among other things. He's actually a Renaissance person, but one of the things he does is looks at infants' development.
And what's interesting about this is this is a newborn interaction with its mother. So this is a new mom and a new baby interacting. And what this is measuring-- whoops, I'm sorry. This is measuring the amount of time, in five-second intervals. So this is a short interval and they're getting longer and longer. So this is a quick face-to-face interaction, and these are more sustained over time. So this is 50 five-second intervals. You can read the graphs.
So essentially, out here means a more sustained face-to-face interaction. And of course, what you can see, which is fascinating, is for the short ones, they're about the same between the low income or middle class and poor family, poor mom. But these more sustained ones, there's a much more marked drop off. So even a newborn baby, in a nonverbal way, in this case, the communication, the attention, the connection, looks like it's different between the middle-income and a low-income parent.
If you look at older children, this is that measure I was mentioning about income to needs, which is that ratio. So one is the poverty line in the US. So this means you're below the poverty line. This means you're between the poverty line and twice the poverty line. Most Americans are between two and four. So this is sort of lower middle class, middle class. This is where most Americans are right here.
This is looking at elementary age children and looking at amount of cognitive stimulation in the home-- books, educational age-appropriate toys, things of that sort, sort of the amount of stimulation, cognitive stimulation. If you look at older children having a computer-- I didn't bring-- because of time-- if you look not only whether you have a computer, if you look is it connected to the internet, if you look at what's on the computer, all very different in relationship to education and income in America.
So low-income families are less likely to have a computer. They're more likely to have games on their computer. They're less likely to have a computer that you can use for educational purposes as effectively. Some people have called this the digital divide.
Participating in literary activities-- so the black is at or above the poverty line and the white is below the poverty line. Do you read to your child every day? This is three to five-year-olds. Did you tell your child, your three to five-year-old, a story at least three times during the week? And did you visit the library at least once in the past month?
So you can see that there's a lot of good reasons why there may be these strong links between income and cognitive deficits or academic achievement falling farther and farther behind as you go on in school. Remember that slide I showed you. They start behind at kindergarten and they continue to fall behind.
Less books in the home-- at the same time there are less books in the home, they're watching more TV. For those of you who are educators and/or parents, could you think of a more lethal combination, more TV, less reading? And that's the same families most likely. So this is not a good mix for cognitive development and academic success.
Just an interesting side comment. I've shown this slide a couple of times in other countries. People are absolutely astounded in other countries at the magnitude of these. They notice, of course, the gradient. Well, you mean the people who are college educated let their kids watch that much TV? So that's an interesting sort of aside about our culture.
One of the myths of poverty is well, low-income families have these great social networks, and they have kinship networks, and they're all interlocked with other people. That turns out to be a myth. That's false. In fact, people who are low income have smaller social networks, they're less connected to people around them, and they experience less social support, not more social support.
Now, that's something that's been portrayed in the media. I think part of the portrayal has to do with people who are resilient, sort of people who overcome the odds, like Oprah. Which of course, becomes sort of the target of all the media attention because we want to try to understand how did they beat the odds. And that's something that's important to understand, but what's also even more important to understand is that person is the exception. You know, most people do not overcome the odds. Most people succumb to the odds.
So this is data from Norway. I chose this deliberately because this is the kind of place where, you know, there's sort of a good social welfare system. It's a social democracy. There's not a lot of real low levels of poverty. There's some, but there's not a lot. And even in a country like Norway, in the case of 16-year-old boys, which is what I pulled this slide, in relationship to socioeconomic status, the higher your status, the bigger the social network. The higher your status, the more time a 16-year-old boy spends with his parents and the less time he spends with his peers.
Now, think about what I'm telling you. A 16-year-old boy-- OK, let me reverse it now. The poorer you are, the poorer you are-- you're a 16-year-old boy-- the smaller your social network, the less time with your parents and the more time with your peers. What does that make you think about? How about juvenile delinquency?
Two to four-year-olds-- this is US data-- exposure to aggressive peers. This is from a national sample by a person named Kenneth Dodge, looking at exposure in very young children to aggressive peers. And here is their sort of scale-- no exposure, monthly, once a week or more. And they're looking at the neighborhood setting, high versus low, the preschool setting. So is it a preschool that's dominated by high-income clients or low-income clients, and the interaction with friends. And you can see a pretty consistent pattern there. So children who are from lower income families are being exposed-- they, themselves, may be generating some of the aggression, but they're also being exposed to a lot more aggression.
SPEAKER 3: Who was rating this? Like, who was saying that they were exposed to the aggressive-- who was saying that the peers were aggressive? Was it a parent?
GARY EVANS: This is not my study. I'm pretty sure it's the parents.
SPEAKER 3: Parents.
GARY EVANS: I'm pretty sure their parents were asked.
This is from the NICHD's national study of early child care. And one of the things that they have become interested in-- they were not at the get-go-- but they've become very interested in social class and income within their sample. Although their sample is actually a very restricted sample. But even though their sample's restricted, they do find relationships between socioeconomic status.
This example is looking at-- this is trained raters, in this case. So these are independent, trained raters. Like, you would be trained to go to this school and rate the teachers' interactions with the children. And what this is referring to here is sort of the make up of the families that go to that center. So this is a center that predominately has lower income families in it. This is a center that predominately has middle class families in it. And these are centers, plural, that have upper class or wealthier families in them. So what you're comparing here are the teachers' behaviors towards the children who are in these different centers that are populated by different background families.
And as I said, this is an independent rating by a trained rater, and there's a pretty clear difference, particularly between this and this. So there's quite a bit more sensitive and less harsh and less detachment, the teachers' interactions with the children in those centers.
If you look at some more structural characteristics of day care-- remember, this is national data-- if you look at the ratio of infant to staff or toddlers to staff-- this is that same study. So these are the centers that have predominance of low income, lower class, lower social class families, predominance of middle class families and upper class families. You can see some pretty big thing.
Look at this one. So the teachers in these settings, it's no wonder that they are behaving in a different way. Part of it is because they're not as well trained. They're not as well paid. And they probably have less experience, although I don't actually know that.
And this is from the third largest school district in California, and it's looking at-- on this axis, we have an index of the income characteristics of the school. And the way they're measuring this is in terms of the share or the proportion of children who are eligible for meal assistance. So essentially, this is the poorest 20% and this is the wealthiest 20% in this large school district in California. So these schools tend to have a larger proportion of wealthy kids or vice versa.
And this is the years of experience of the teachers in the school. This is the percentage of teachers in the school that have a graduate degree. So remember, over here you've got-- these are the schools-- this is the poorest quintile or 20%, and this is the richest 20%.
So I've shown you kind of a snapshot that there is lots of reasons we might start to understand why is poverty bad for children, in terms of psychosocial characteristics of the environments that they grew up in. And of course, we not only live in a psychosocial situation, we also live in a physical environment, and those, too, often interrelate to one another.
And there's a movement in-- I'm not actually sure when it began-- but called environmental justice, or sometimes called environmental racism. If you're not familiar with that, what started that was mainly community groups and some political activists noticed that there seemed to be some correlations, some links, between environmental quality and people's backgrounds, and particularly, that low-income people and in some communities, people of color, seem to be confronted with more physical environmental problems. And that's called environmental justice or environmental racism if you're interested in it, if you'd like to learn more about that.
Well, of course, children are growing up in these environments, as well. And as I will show you, some of the physical characteristics that are linked to poverty, you can readily imagine links to children's development. I'll point out some of them in passing because there's too many for me to go into it in all of them. But I'm presuming that you may be a little less familiar with some of the relationships between the physical environment and child development than you are from some of the psychosocial things that I've been showing you.
So remember that study of the way the teachers interacted with the children in the different day care centers. Well, this is a similar study, looking instead of the quality of the teacher/child interactions, actually looking at a standard index of the physical quality of the day care center. So day care centers with more low-income kids versus day care centers with more middle and upper-middle income kids, it's not a perfect linear relationship, but it's pretty clear that here you've got a lot lower quality.
Same thing in high schools and middle schools throughout the United States. Here you've got percentage of kids eligible for free or subsidized lunch, and this is the percentage that have less than adequate facilities. The GOA, the General Administrative Office, did a very thorough analysis early 2000-- yeah, about 2000-- of all of the school plants in the country because there's a lot of concern that we're not dealing with the infrastructure of our schools. 60% now of New York City public school buildings have one or more serious deficiencies in the structure of the building, 60%. So this is a problem that's kind of a sleeping giant that's going to come out and bite us. Sort of like when the bridges go bad, the schools are going bad.
And what you can see here is, in particular for the permanent additions, which are the black bars, there's quite a gradient between having more wealthy kids versus having more poor kids. The white bars-- if you're wondering, well, how come there's no link there? Well, these are the original buildings, and when these buildings were originally built, the income characteristics of who was in the buildings was different. So this more closely tracks the income characteristics of the buildings at the time these additions were made. So that's why you get a stronger link here. But in general, you can still see the same pattern. So not only are you more likely to have a day care facility that may have lower quality, it's probably also true when you get into middle and high school.
Access to parks, access to open space, places to play are related to income. Other places you can exercise-- most of you are acutely aware of a lot of concern about an obesity epidemic in the United States. Very strong class gradient between obesity and income levels. One, not the only, but one of the reasons probably has to do with the ability to find places to be physically active. Diet is also going to be related to it, as well, of course. But part of that obesity epidemic and it's link to income and class may be related to data such as these, less places to play outside, less park space, less resources.
You're supposed to eat healthy and not eat junk food. Well, it turns out that buying healthy food is much harder in small 7-Elevens, delis, things like that. If you want healthy food, it's easier to find it-- tends to also be a little bit more reasonable in price-- in a supermarket. Look at the link between neighborhood income levels, OK-- this is per capita, so they're controlling for the number of people-- and then supermarket availability, so poor to wealthy.
So all these people here that were saying, look, you've got to exercise, you've got to eat right, et cetera, et cetera, because you're getting too heavy, you're getting diabetes, et cetera, all of which is sadly, true. There's a lot less places to go buy that healthy food.
Housing quality-- this is looking at deciles and quintiles. I really don't know why. Someone was torturing us. But this is the lowest tenth in income and this is the highest fifth in income. These are national data and these are percentages of homes. So within this decile, 2.5% have an incomplete bathroom, and as you can see, 0.6% in this quintile have an incomplete bathroom. These are from census data. So these are actually very large population statistics.
Remember the thing about asthma? A trigger for asthma is dust mites. This is looking at the presence of dust mites in the home in relationship to income levels. So low income homes, at least in this particular study, which was done in Detroit, have much higher levels of dust mites, which is a trigger for asthma.
Crowding-- people per room is one of the most important ways to measure crowding. I'll give you an example. Here's one that's more subtle. Well, why would crowding possibly be related to children's development? So you can see that crowding is clearly related to income. That's no surprise, right? What does money buy? Among other things, that buys you more space. So that's all this is showing you. So as you get richer, you buy more space, OK?
Why might crowding be related to a child's social or cognitive development? Think about if you were a parent in a very, very crowded home, a lot of people per room. So that's what we mean by crowded. People per room turns out to be the most crucial. What do you think you would do to cope with that? So you live in an environment that's very crowded. How would you cope as an adult with that? What strategy would you use to deal with that?
SPEAKER 4: Would it be-- it's sort of that confluence again, where it would be more stressful, more aggression, so maybe alcohol abuse or separating yourself from the kids, making the older kids watch the younger kids.
GARY EVANS: You hit button on the last one-- separating yourself. Think about in your own situation. What do you want to do when you're feeling crowded? You want to withdraw. One way to think about crowding is too much on one in social interaction is kind of a psychologist's definition of crowding-- too much on one in social interaction. So what do you when you're crowded? Well, you withdraw. The problem is that may become a strategy that becomes adopted, almost becomes sort of your way of dealing with people in general.
So there's some research, for example, showing that if you take college students who live under more crowded environments and you bring them into a laboratory under very well-controlled conditions where it's not crowded, they're more withdrawn. So it may become sort of a style, a habitual way that you start to interact.
And of course, we know that responsiveness or sensitivity of parents to children is an important feature of healthy parenting and leads to better develop. So crowding may actually have this sort of very subtle, pernicious fact that's not obvious on the surface.
Noise-- this is a British study. This is using the eligibility for free lunch. This one's a little harder to understand, so I'll slow down on this one. So this means that in this particular environment, these schools-- these are plural. These are multiple schools. The average percentage of the schools in the low noise zone, the average percentage of children in these schools eligible for a free lunch in Britain is 14%, OK? So schools that are low levels of noise, 14% of the kids in those schools are eligible for a free lunch.
Over here, you have very noisy schools. So these schools are located in very noisy areas, which in this particular case, means they're near an airport, OK, actually Heathrow, if you want to know the details. And you'll notice the difference-- 14%, 28%. It literally doubles.
Now, there's one other little thing about this that's important that some of you might find interesting. See these little numbers here? 57 leq, 57 to 63, 64 to 72. What do these mean? These are the measure of the sound intensity in decibels. Decibels is a measure of sound intensity. Here's the interesting fact. Decibels are logarithmic. So this to this is twice as loud. A 10 decibel change is perceived as twice as loud. Think like Richter scale and earthquakes. It's kind of the same kind of idea. This is a logarithmic scale.
So these schools compared to these, these are approximately twice as loud as these schools are. And notice the percentage of low-income kids here versus here. So it's more crowded where you live. It's noisier where you go to school.
Whoops. Polluted-- it's much more polluted. These are wards in Britain. Wards are like counties. These are in tenths. So this is the richest 10% of the counties in Britain, and this is the lowest 10% of counties in Britain. And as you can see, what they're looking here is carcinogen. These are cancerous emissions that are either known or suspected to cause cancer, in relationship to the location of the factory. So these are low-income counties, and these are wealthy counties.
Same thing in the US. This is St. Louis. Social class of neighborhoods in St. Louis-- not counties but neighborhoods-- sulfur oxides, which is one indicator of pollution.
Lead-- you're probably familiar with the difficulties and challenges of lead. I suspect you've had some discussion or lectures about that before. You may or may not know that lead is strongly linked to income levels in the United States. So low-income families are much more likely to have lead exposure.
This is the current US standard, which most people now agree is too high. So this is not safe enough. We need to push this down. Probably not going to happen right now because of the economic situation but eventually, this will probably get cut. And you can see here a pretty strong link between income exposure and exceeding what the standard, which is the current safety standard in the US, which as I said, is probably too high.
Living near a hazardous waste dump-- this is Detroit. So you live within one mile of a hazardous waste dump, approximately 30% are below the poverty line. If you live more than a mile and a half away, you cut that by a third, now 10% are below the poverty line. So you're within a mile, 30% of you are poor. You're a mile and a half away, 10% of you are poor.
This one also is giving you some data on ethnic minorities. People of color are also much more likely to be near a hazardous waste dump. 50%-- I'm rounding off a little bit-- 50% and 20%. So this is a nice example of this thing some people call environmental racism or environmental justice. So if you're poor and you're of color, you're much more likely to be living near a hazardous waste dump, at least in Detroit. And there's data in other parts of the US showing similar things.
Crime, of course, is related to poverty and income levels. So a lot more crime in low-income neighborhoods. I don't think that's a surprise to anyone.
This is another slide when I show it in other countries, people think that I made a mistake because they can't believe the levels of these. These are high school students who are from blue collar families or white collar families. And they're asked are there any guns in your house, is fighting a problem in your school, are weapons a problem in your school, and do you fear for your safety in your school? And as I said, when I show this slide in other countries, people are sort of, did you make a mistake? You have weapons in your school and people are worried about that? But anyway, you can see the differences between poor kids, in this case, working class-- we're not even talking about poverty here, just working class-- and sort of professional and middle-class kids.
So part of what I'm trying to argue is one of the reasons why poverty may be bad for kids is because we get this confluence. We get this-- you have a lot of these different things going on. But what happens when they go on at the same time? So what happens if you're the family that has the lead and goes to the school where there's a lot of violence and it's polluted outside, and it's crowded, and there's more conflict and turmoil, maybe there's more problems in the household relationships. You have teachers at your school who are less experienced, et cetera, et cetera.
So one way to think about this is part of the reason why poverty is bad for kids may be because of exposure to multiple stressors.
We go to what time?
SPEAKER 5: Noon.
GARY EVANS: OK.
These are data from an old friend of mine named Arnold Sameroff. Arnie is a developmental psychologist, actually an infancy researcher, who used to be at Rochester but unfortunately, he's not there anymore. He's out in Michigan now.
And what he's showing here is what happens to different kinds of developmental outcomes-- different kinds of developmental outcomes-- as a function of the number of risk factors that you're exposed to. The term for this, if you're interested, is called cumulative risk. And what it's showing is something that probably would match your own intuition, which is as risk exposures accumulate, things get worse and worse and worse. And this is a composite of multiple studies of Arnie's, a couple of different samples that Arnie and his colleagues have been looking at in Rochester, Chicago, Philadelphia, at least are three that I'm aware of.
And so this is a very typical pervasive relationship that you'll see in child development, which again, I think kind of just makes good sense, right? So if you have one risk factor, there will be some kind of a negative outcome. If you have two, if you have three, it gets worse and worse and worse. So this actually girds the argument that maybe one of the reasons poverty is bad for kids is because they're exposed to more of these cumulative risk factors. Because we know from these data and other data that when you're exposed to a lot of these risk factors, a lot of bad things happen.
So if you put those two things together-- higher exposure to cumulative risk, and we know the cumulative risks are linked to poverty. That's what I've just been showing you. It starts to become a plausible pathway.
So I'm going to tell you a little bit about a study. This is a study in upstate New York, and it's a poverty study. So unlike a lot of the studies that I'm showing you, this study was designed to look at poverty. So roughly half the sample at the beginning are below the poverty line and roughly half are two to four times. Remember, this is where most Americans are. So this is sort of the great unwashed middle class, right? So this is lower middle, middle class, mainly a White sample. Rural-- it's upstate New York. And the mean age at the beginning of the study was nine years old.
Because this study was designed to try to take a look at this idea, what we've done-- my students and I have selected a subset of risk factors and we consciously chose some that were physical and some that were psychosocial because of what I've been talking about. So what we're going to do is we're going to characterize exposure to these different risk factors.
Here's how we do it. We can talk about that later if people are interested, but essentially, each risk factor is dichotomized. You're exposed? Yes or no. So you're in a crowded home? Yes or no. And that's done on a statistical basis in this particular study, which is essentially if you're on the upper tail of the distribution. So if you look at a frequency distribution of density, people per room, if you're high, on the high end, more than one standard deviation above the mean, for crowding you would get a one and everybody else would get a zero.
And we do that same thing for noise levels, using those decibel meters that I showed you. And we have housing quality, and this is trained raters evaluate housing quality.
We also look at some psychosocial stressors. In the early parts of the study, when the kids were younger, this is coming from the mom's report of things like family turmoil, child separation from the family, exposure to violence. This is both inside the home and in the neighborhood. So this is maternal reports. Later on, we add in, as children get older, their own judgments about these, as well.
These are just reflecting what I've been talking about with a particular small, specialized sample, which is upstate New York, White, rural. Just like all those other data that I was showing you, that the low-income families are more crowded, it's noisier, and they have a lot more housing problems.
They have a lot more family turmoil. The child is more likely to have been separated from the mom at some point or the dad, and there's more violence.
Here's where it starts to get interesting. Remember, there were six of these? There were three physical and three psychosocial. And each of them is dichotomized. You're exposed, one, or you're not exposed, zero. So that means you could create an index, which would go from 0 to 6. So a zero would mean you're never on the top end on any of them a 6 would mean you're on the top on all of them.
So what this is trying to do is trying to operationalize this idea of confluence. So in other words, the family is out on this, and there's a lot of convergence of risk factors. And of course, it's highly linked to income, which is exactly what you would expect. So down here, the zero is much more likely in the middle. One is much more likely in the middle. They're about the same. And then it breaks out quite clearly. So when you start to get more and more of these things happening, much more likely that you're a low-income family.
And remember that slide from Sameroff? What was the link between the cumulative risk and the outcomes? Remember that, right? So let's look at some outcomes. We're going to look at some mental health. We've got a maternal rating of psychological distress. The child's own rating of his or her-- these are nine-year-olds-- sort of this is kind of like a self-worth, sort of low level-- well, pretty much what it says, self-worth-- self-esteem, pretty similar.
This is a task that was developed by a psychologist named Walter Mischel. And one of the characteristics of children who don't do very well at school is something called impulse control problems or the fancy word is executive function deficits. One of the indicators of that is that you cannot inhibit behaviors when you need to. So this is a way to measure that kind of behavior that was developed by this psychologist, out at Stanford, who's actually now in New York City.
And what his group did was they tried to come up with a way to measure delay of gratification in a systematic way. So essentially, what you do and in hindsight this was not the right way to do it, but nonetheless, that is the way we did it in this study. Is you give a child two plates of candy. One's a big plate and one's a small plate.
And you say, which plate would you rather have? We all know the answer to that question, OK? So what you-- OK, the one that you'd like to have, I put that right in front of you. And I say, if you can sit here for a little bit-- I have to leave the room-- if you don't get out of your chair, you don't touch the candy, you can have this big one. But here's a little bell. If you can't wait, ring the bell and I'll bring you the small plate of candy. OK, do you understand what's happening? So you're sitting there delaying gratification. If I wait, I get the big plate of candy. So of course, what you can measure is how long do they wait and do they wait successfully up to a total of 30 minutes?
We also measure blood pressure as an index of physiological stress and these are stress hormones, which are secreted in your body when there are more environmental demands on you. The kids are rated by their moms as more stressed here, here. The children rate themselves as lower in self-worth. These are nine-year-old children, and they're much less likely to successfully delay, and they don't delay as long. So these low-income kids in this upstate New York sample relative to their middle class counterparts, are having more difficulty delaying, self-regulating. Another term for this is called self-regulation. Can you regulate your behavior? Or impulse control would be another way to think about it.
And they have higher stress hormones in two cases, cortisol-- this is sometimes called adrenalin and noradrenalin. These are the same things, European and North American words. So these two are statistically significant. This one's actually not different, even though it looks like it ought to be. And they have higher resting blood pressure. This is when they're relaxed. They're just sitting there. These are nine-year-old children. So nine-year-old children from low-income families have higher blood pressure at rest. The stress hormones were measured overnight. So those are also probably indicators as sort of their chronic, resting baseline levels of these stress hormones secreted by their bodies.
SPEAKER 6: Are there any things controlled for [INAUDIBLE]?
GARY EVANS: Oh, yeah, yeah.
SPEAKER 6: So like race and gender and various things are controlled for.
GARY EVANS: The effects on these look a little different by gender, so I'm kind of ignoring that. You get the significant effect. Looks like the effect's a little bit stronger for boys.
I'm not going to go into this but essentially what this is doing is this is some statistical analysis looking at this, trying to test this question. Do the exposure to these cumulative risk factors help explain the link? And the answer is yes, it helps explain the link. It does not explain the entire link, which is also what I expected, because I'm not arguing that the only reason or that the sole reason why income causes trouble is because of cumulative risk but I think it is one reason.
This is looking at the same families when the children are 13 years old. This was that poverty, middle income. This is cumulative risk. So this is zero and this is four. Now, you'll notice there's a little less out here-- attrition. The families with the most risk factors unfortunately, are much more likely to drop out of the study. Not surprisingly, they're the families that have a lot more problems. They're the ones that are really on the high end. Which of course, is unfortunate, in the sense that since I'm trying to estimate the links between poverty and the role of cumulative risk, I'm sort of shooting myself in the foot because the people with the most risk drop out of the study over time. That's a common problem in these kinds of studies.
We're looking at similar things-- mental health from the youth, self-regulation. Now, we're going to ask the teachers about some things. We're going to ask the teachers about problems at school. We're also going to add in a task looking at learned helplessness, which I'll explain in a second and some of these same physiological measures. And we're going to look at grades.
So this is psychological distress. This is the child-- actually the youth, they're 13 now. So this is a rating by the youth. This is a rating by the teacher of your ability to regulate. So the teachers of the middle class kids say they can regulate better. The children themselves say that they have more psychological symptoms, and the teachers say that that low-income kids have more behavioral problems.
This is a very interesting index. This essentially is looking at a situation where you're confronted with a task that's challenging and difficult. How long do you persist at it? So you could think of it as sort of task persistence. Maybe how tolerant are you for frustration could be part of it as well. So it's essentially like a jigsaw puzzle that they're trying to solve, and we're interested in how long they sort of go at it and the low-income kids essentially give up sooner. They're less persistent and their grades are lower, which, of course this just matched data I showed you from earlier. This one.
In addition to measuring their resting blood pressure, we also-- when they were 13-- added some complications to some of the physiological measures. And in addition to measuring their resting blood pressure, we're measuring something called reactivity and recovery. Reactivity means if I confront you with an acute demand, a mild stressor, as you would intuit, your blood pressure will go up. What we were interested in was how high would it go up, and would how high it goes up be related to your income background, whether you're from a low-income family or a middle-income family?
In addition to how high up it goes, how long does it take you to come back down to recover, all right? That's called recovery. So I have this resting measure, which I kind of use as my floor, my baseline. I then exposure you to a mild acute stressor, doing a mental arithmetic task in this particular example. And I look at how high up does your blood pressure go and how long does it take you to come back down.
What you can see here is something that you might not have intuited. You might have thought, well the kids who are low income are more stressed. They're going to go up more. They go up less. So the poor kids actually go up less compared to the middle-income kids. Both of these are statistically different. So relative to their baseline, the low-income kids go up less. And that could be because their baseline is higher. We control for that. That's not what it is.
What we think it is-- so we think this may be indicative of actually chronic damage to the physiological stress system. There is some work with animals, a little bit with people, suggesting when you have chronic stress over a long period of time, one of the symptoms of damage to that system is you become less efficient at mobilizing when you need to. So stress, as you know, is an emergency response that's adaptive. The problem with stress is when we turn it on and off too much. But without stress, none of us would survive. We need to have that emergency response system. The problem is, if you keep turning it on and turning it off, you may actually do some damage.
One kind of damage, perhaps, might be that you actually interfere with the ability of this system to respond appropriately when it should. So if you're supposed to perform on a math test, you need to mobilize. That means you need to increase your arousal levels. You need to increase your energy. These children may be less able to do that.
They also have higher cortisol. I didn't put it in here. Maybe I did. Let me see. No, I didn't put it in. They also take longer to come back down. So they go up less-- they go up less, and they take longer to come back down. So that's a very strong finding.
Another way to think of it, if you're having trouble getting a handle on it, imagine like if you went for a run, right? So when you go for a run, your pulse goes up, your blood pressure goes up, OK? That's, like, the reactivity part. Then you stop. That's the recovery. How long do you get back down to the resting pulse? That's sort of what we're doing, except we're not running. We're giving them a mental arithmetic challenge.
I thought I would end talking a little bit about sort of where some of this kind of work is going. And all the different kinds of effects of stress have led people in the last, probably 10, 15 years to become very interested in well, what about the brain? Does stress affect the brain? And if it does, might there be a relationship between the brain and poverty? Because if stress affects the brain, and if low-income people and children, in particular, are facing and confronted with more stressors, then maybe their brains are affected by poverty.
So this is sort of where this field is, just-- this is kind of where the cutting edge is, kind of where people are going right now. This is a brain, very oversimplified. Talking about different areas of the brain, and they are labeled here. And some of these areas of the brain are related to certain functions. So the prefrontal lobe up here is related to working memory, executive control, think delay gratification, remember, maybe processing of rewards. This part of the brain may be related to language.
So this is a study done by Martha Farah at Penn quite recently, as you can see. And what she's showing here is essentially-- the height of the bars means the stronger the effect of poverty. And this is a study of low and middle socioeconomic status children. Let's see, in this study, they are elementary school age, and these are effects on these measures associated with those parts of the brain that I was just showing you. So in other words, what she's doing is comparing low socioeconomic status children to middle. So it's cross-sectional comparison, in terms of areas of the brain that are reasonably well-coded. So she's got a task that's measuring language, which is highly associated with a particular part of the brain.
And you can see here, language, working memory, remember the cognitive control, the executive control, long-term memory, spatial and visual cognition. The gray means they're not statistically significant, although she has a small sample. Given the effect sizes, these probably would be significant in a larger sample. But anyway, so language is huge, as you can see. And both of the memory ones and the control are pretty big. These are pretty reasonable effect sizes.
This is the kids from the upstate New York study, and this is looking at their working memory when they are 17 years old. So we now have another wave of data, which I don't have time to show you a lot about but I can show you a little bit.
So they're 17 and we're looking at working memory. So this is an index of working memory. And this is the proportion, misspelled, the proportion of their life spent in poverty. So essentially, this is a kid that's never been poor, and this is a kid that's always been poor from zero to 13. So age zero to 13, at age 17, you have less working memory capacity. This is related to an area of the brain called the prefrontal cortex.
Now, what's interesting about this is the following. This is a relationship, the same thing on the x-axis, proportion-- with the R there this time-- of your life in poverty and an index of kind of a composite index called allostatic load. This is a composite index of those physiological stress measures. So sort of a composite of them. And as you would expect, the greater the proportion of your life in poverty, the higher this physiological stress between birth and 13. So this has got three waves of data in it-- two waves of data predicting a third wave.
This relationship between proportion of life in poverty and working memory goes away when we control for the chronic stress. So there's some suggestion, by no means proof, that there may be a link between brain development and poverty that may be partially explained by chronic stress. Now it's an indirect argument because we have a measure of stress, physiological stress, during childhood and we have a measure of working memory that we know is tied to a particular part of the brain called the prefrontal cortex. And we know from other people's work that the prefrontal cortex is sensitive to chronic stress. So the data here suggests that. They, by no means, are proving this.
But there's certainly kind of suggestive evidence that a lifetime of poverty may change, may cause some cognitive deficits, which is well-documented in lots of studies, including this one. But part of the reason-- this is the first time this has been shown-- part of the reason might be related to stress.
And I've got one final slide, which is a little hard to see. This is a study, very recent study from a person at University of Pittsburgh. And he did FMRI brain scans of people who are low and middle income and there are differences in the structure and activity of their brain in this prefrontal cortex. So the brains-- this is adults. So the brains in adults of people that are poor look different in this area called the prefrontal cortex. So this is sort of where this-- kind of where this field is going right now.
ANNOUNCER: This has been a presentation by Human Development Outreach and Extension at Cornell University.
Watch the full presentation with speaker footage and slides .
Gary Evans provides an overview of the social and physical characteristics of settings that low income children grow up in and discusses what we know about why poverty is bad for child development.
