The Causes of Poverty (52): Brain Dysfunctions Caused by Early Childhood Adversity

Children in orphanages, in poor quality day care centers, children of teenagers or children with one or two parents incarcerated often experience neglect, lack of stimuli, adversity and even abuse. Studies have shown that this kind of adversity, especially if it takes place during the first two years of life,

can damage the brain as surely as inhaling toxic substances or absorbing a blow to the head can. And after the age of two, much of that damage can be difficult to repair, even for children who go on to receive the nurturing they were denied in their early years. … For a long time, social science has known of correlations between childhood turmoil and all sorts of adult maladies that carry massive social and financial costs—mental illness, addiction, tendencies toward violence. … [Recent] science suggests that many of these problems have roots earlier than is commonly understood—especially during the first two years of life. … [A]dversity during this period affects the brain, down to the level of DNA. (source)

Early childhood adversity such as neglect, abuse or the stress produced by extreme poverty weakens and distorts the development of the brain and sets the body’s hormonal stress function on permanent high alert.

Here are some examples of the ways in which early childhood adversity affects the brain in a lasting manner:

[A] baby who endures prolonged abuse or neglect is likely to end up with an enlarged amygdala: a part of the brain that helps generate the fear response. Some of the earliest and most important research establishing this process dates to the 1950s, when investigators observed that rats were better at solving problems if they got more nurturing at very young ages. … Subsequent research showed that persistent childhood stress also leads to significant physical problems, such as far higher rates of cardiovascular disease and diabetes. … Early adversity … can interfere with planning ability, cognitive flexibility, problems with memory, and all of those will correlate with diminished IQ. … One 2010 paper from Psychological Medicine concluded that “childhood adversities”—a category that includes abusive parenting and economic hardship—were associated with about one in five cases of “severely impairing” mental disorders and about one in four anxiety disorders in adulthood. (source)

So there is evidence of a causal connection between trouble in very early childhood and problems that occur later in life. Notwithstanding the fact that some affected children end up OK and that others may benefit from later interventions, the cited effects are often tenacious in later life. That means that preventing them requires concentrated action during those crucial first two years. Providing very young children with stable, responsive and nurturing relationships in the family, in school and in the neighborhood can prevent or reverse the effect of early childhood adversity, stress and neglect.

And the interesting part from our point of view is that the effects of early adversity are not limited to mental disorders and crime. These effects cause and perpetuate poverty. Hormonal and brain functions that are distorted by adversity and stress result in learning difficulties:

Children who fail to develop coping mechanisms struggle from the earliest days in school, because even the slightest provocations or setbacks destroy their focus and attention. They can’t sit still and read. They have trouble standing in line. They lash out at classmates or teachers. And these struggles, naturally, lead to other problems that perpetuate the cycle of poverty. All of this is to say that the science of early childhood may play a significant role in the dominant political question of our time: rising inequality. (source)

That means that anti-poverty measures should focus on very young children. Such measures have lifelong benefits for learning, behavior and health. Not only are such early measures more effective in the struggle against poverty than attempts to reverse damage later in life – they are probably also less costly.

More posts in this series are here.

The Causes of Poverty (26): Hereditary Poverty, Another Poverty Trap

For you always have the poor with you, and whenever you wish you can do good to them; but you do not always have Me. Mark 14:7

For the poor will never cease to be in the land; therefore I command you, saying, “You shall freely open your hand to your brother, to your needy and poor in your land”. Deuteronomy 15:11

As a result of having parents who are poor, children

  • receive substandard education because they enroll in substandard schools (if at all)
  • may be forced to quit school early and start working
  • do not receive quality healthcare (because of the costs)
  • are more likely to be obese, with negative consequences for their health
  • have a lower birth weight, something which also has a negative impact on health.

Growing up in poor families has negative effects on children’s education and health, and these effects in turn make it more likely that these children grow up to become poor as well. And their children will go through the same process, and so on. Hence the concept of hereditary poverty.

Just a few more words on the effect of substandard education. The quality of schools (or better the cost of good schools) and the element of child labor aren’t the only factors limiting the education levels of children in poor families. An interesting article in The Economist points to effects discovered by neuroscience. It seems that stress, induced by poverty, lowers memory capacity, and this lowered memory capacity makes it more difficult to learn and to obtain a good education as a means to escape poverty traps. It’s been well known for a while that stress lowers memory capacity (it reduces the volume of the prefrontal cortex and the hippocampus, parts of the brain associated with memory). However, Evans and Schamberg (see the paper here) showed that stress caused by poverty reduces memory capacity. First they showed that poverty is correlated with higher stress, and then that higher stress is correlated with lower memory capacity. Comparisons of the memory capacities of poor and middle class people showed indeed a difference in memory capacity, and this is caused by poverty induced stress rather than other elements of poverty. Poverty causes stress, which reduces memory, which in turn makes it harder to learn, which in turn makes it more difficult to escape a poverty trap. How does poverty cause stress? Well, there’s the obvious cause: financial insecurity. But low self-esteem caused by poverty (including for children in poor families) also seems to contribute. See this paper for instance.

The poor indeed will always be with us. At least if we don’t help them to get out of the traps in which they find themselves.