The Brain Science Behind Behavior

Poverty, inequality, and the long lasting impact of adverse environments.

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This article continues the series The Brain: A Primer for the Novice, and behavior in particular, sharing observations from Robert Sapolsky’s fascinating book Behave: The Biology of Humans at Our Best and Worst. For a brief summary and introduction please read the previous blog first.

This article aims to share a few interesting observations:

Childhood adversity biologically impairs brain development, learning, and memory. It also leads to the risk of adult depression, heightened sense of fear, anxiety, decreased behavioral regulation and impulse control, damaged dopamine system which can lead to increases in drug craving, poorly developed inhibitive aspects of the prefrontal cortex. The implication here is staggering — in addition to the other disadvantages that childhood adversity brings, there are mid and long term implications on these unfortunate children’s ability to learn, socialize, and progress EVEN once out of those environments. I don’t think we needed more evidence, but here was clear biological studies and evidence showing the OUTSIZED criticality of supporting struggling families and children growing up in adversity. Much less about race, effort, and more about not getting the necessary environment to set children up for recovery, catch-up, learning and success.

Relatedly, there was a great TED talk that highlights the need for schools to take child emotional development seriously and shares some techniques teachers and schools can utilize. An underinvested area with incredible importance and high leverage implications for our future generations.

Environmental impacts can be passed on genetically or more precisely, epigenetic changes can be inherited, multi-generationally. The prevailing dogma was that all the epigenetic marks (i.e., changes in the DNA of surrounding proteins) were erased in eggs and sperm. But it turns out that epigenetic marks can be passed on by both (e.g., make male mice diabetic, and they pass the trait to their offspring via epigenetic changes in sperm). The implications are that the effect of your parents' or grandparents’ environment — environment not just genes — can be inherited and passed down through the generations. This is remarkable and really compounds the negative long-term impact of childhood adversity; and heightens the long-term needs to help those that have struggling environments not pass those challenges on to the next generation.

Testosterone doesn’t drive aggression. It drives behaviors needed to maintain status: “Testosterone makes us more willing to do what it takes to attain and maintain status. … Engineer social circumstances right, and boosting testosterone levels during a challenge would make people compete like crazy to do the most acts of random kindness. In our world riddled with male violence, the problem isn’t that testosterone can increase levels of aggression. The problem is the frequency with which we reward aggression. If you are already aggressive, testosterone amplified it.” This was an interesting observation and contrary to my common belief, but the reality is that variations in testosterone level don’t predict aggression; but make us more sensitive to triggers of aggression.

Oxytocin causes us to treat strangers poorly. Oxytocin — the so-called “love hormone” — generally is known to decrease stress and anxiety, enhance trust and engender generosity and cooperation. However, this hormone only works with our “In” Group. When dealing with others — our “Out” Group — it actually drives us to protective, insular, antisocial behavior, treating strangers poorly for example, and making us more xenophobic. While this is our innate capability and perhaps drives mamma bear type instincts, as described in the previous blog, cognitively this behavior can be overcome.

Socio-economic inequality causes stress more than poverty itself. This bears repeating because it’s not intuitive: “its not so much that poverty predicts poor health; its poverty amid plenty — income inequality”. According to Sapolsky, there is a mammoth amount of literature that demonstrates that income inequality is a greater predictor or poor health than poverty. Some reasons explained are that it’s a function of lack of control, predictability, outlets for frustration, and social support that activate the stress response which corrodes health in numerous ways. This is a profound finding and tracks what we intuitively believe about individuals in lower income countries being happier than the “less poor” in our own countries. Rather than blaming the poor in our country, perhaps we should take more understanding from these studies and acknowledge that the effects are indeed real. And as if we needed additional reasons to attempt to address poverty and inequality — straight up health implications are another.

And last, one interesting meta-observation from the book is that while interesting and certainly educational, neurobiology should not be needed to confirm the obvious. It’s an odd human bias that things that appear “obvious” sometimes feel more “real” when brain research shows them to take place biologically. We shouldn’t need a biological explanation: for one our biological tools and research are still primitive (showing brain areas lighting up, etc.), and two they don’t make the results or implications any more real. The behaviors can be understood, analyzed, and acted based on the behaviors and environments themselves — without needing to demonstrate biological causality inside the brain. I confess that I fall into this tantalizing trap myself, so it was an important insight and helpful reminder.

The big take aways from my reading on biology and behavior is that a) don’t judge other people’s behavior without understanding their full circumstances, environment, brain chemistry b) we should work extra hard to help those in poor or adverse conditions and environment c) it takes extra effort — awareness, cognitive “protection and care, and habituation — to understand and positively affect our behaviors.

This article is part of a series of posts about the brain. Feel free to check out the start of the series here which includes links to the other articles on neuroanatomy, behavior, learning, AI, and free will.