Is human behavior “a magnificent, fascinating, nuanced interaction between nature and nurture”? To what extent is our behavior controlled by our biology and to what extent does our behavior control our biology? What is the nature of a biolgically-based human being? What is unique about the behavior of humans in the animal kingdom?

These questions are the broad concerns of the 25 videos totalling 36 hours and 40 minutes constituting the free on-line edition of Stanford University’s Bio 150 course “Human Behavioral Biology” recorded in the spring of 2010 with Robert Sapolsky. The course is an accessible yet scientifically detailed introduction to modern biology’s understanding of human behavior. It is a broad biology-centered approach where animal comparisons and a broad systems perspective engage a way of understanding our psychology without too much solipsism. Sapolsky’s gift for story-telling and his style of boldly confronting the moral implications of his poignant topics make the lectures engaging edutainment. Topics include sexuality, violence, language, mental illness, religiosity, and individuality which are explained using the main biological subjects of evolutionary theory, genetics, ethology, endocrinology, and neuroscience.

Although I finished studying “Human Behavioral Biology” in July 2016, its continued influence on my thinking and the diffuse locations of my notes has led me to want to document its highlights, my notes on the videos, and the events I organized to explore aspects of the course in small groups. Hence this summary.

Perhaps, Sapolsky’s most profound contribution to my thinking came in the first lecture in his course where he composes a list of the dangers of categorial thinking:

1. We can miss the big picture by focusing on boundaries.
2. We tend to underestimate differences when two cases happen to fall in the same category.
3. We tend to overestimate differences when cases happen to fall on opposite sides of a boundary.

Of course, as Sapolsky himself acknowledges, categories are essential scaffolding for our thinking. In fact, I cannot imagine how we could think at all without some distinctions, some categories. But these profound dangers affect every distinction, every assumption, and every taxonomy that we might entertain. For me, this realization was stunning, profound, and transformative. Do you see the significance? Can you imagine the comport of its implications?

Another important aspect of the course was to better understand the profound interrelationship between genetics and environment. For me this really hit home when Sapolsky explained how the cure for one of the most devastating single-gene mutation diseases known, PKU (phenylketonuria), is treated with a simple modification to one’s diet; a genetic disease “cured” by a simple change to the environment! Nature and nurture are both categories that belie the far more subtle and interfused gene-environment interaction. That and the treatment of epigenetics, transcription factors, life history including perinatal development, and the limitations imposed by the requirement of controlled experiments in science gave me a much clearer understanding of how the gene-environment interaction belies many widespread but erroneous assumptions and studies in genetics.

Another significant feature of the course is the way it engages complex systems thinking by looking at the determinants of human behavior from most proximate to most distal: the behavior itself and its releasing stimuli (ethology), neurobiology, acute and chronic hormonal environment, perinatal biology & environment, culture, genetics of the individual, ecological and environmental context, and evolutionary history. Should we think of all causality as this kind of multi-layered, intricate confluences of many overlapping and interconnected systems? I think so! And Sapolsky gives a feeling for this way of thinking that is remarkably effective, if you put in the effort to think it through carefully.

Saplosky’s lectures boldly face many of the challenges posed by our modern understanding of biology as applied to human behavior. His engaging lecture style never shys away from controversy so he can address, with accessible but scientifically nuanced detail, broad questions about biological determinism and the biology of morality.

Below I present my curated edition of the course. It will, I hope, help you get even more out of the videos. It might even help you organize your own events to explore on ideas in the course with others. At the end I invite your feedback on this curation, and the materials it includes, and on the prospect that this kind of curatorial approach to organizing group explorations might prototype a new educational service to help our civilization better address its crisis of ignorance.

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Although I have always been interested in the mind and thinking, I have been suspicious of psychology and the cognitive sciences. Recently, I’ve been impressed by several TED Talks that address new ideas in the sciences of the mind. These subjects are starting to provide valuable insights into how the world really works. It is still wise to be skeptical, but we might have made enough mistakes in psychology that we now have some groundwork upon which to start figuring out what is really going on in our heads.

So I was delighted with the chance to go into more depth in the science of decision making by reading Jonah Lehrer’s 2009 book How We Decide and participating in a discussion with the Ben Franklin Thinking Society. First, some overall impressions of the book. I thought Lehrer gave a good account of how the emotional brain works and some strengths and weaknesses in our decision making. I really value how he presents so many examples of experiences and experiments to illustrate the subject. His conclusion, though adequate, did not bring it altogether for me (cognitive dissonanace is a good thing and it helped me write this post!). Jeannie was turned off by Lehrer’s bone-chilling accounts of airplane crashes and psychopaths. However, we both learned a lot about the neuroscience of decision making. For me it was a good read, if not a great book.

The nature of emotions

One major omission from the book was the lack of a diagram showing the relationships among the brain regions discussed. Jeannie drew a rough sketch entitled Brain Turmoil below to give some sense of how the pieces fit.

Apparently, the brain uses dopamine-mediated “prediction” neurons to recognize patterns (a dopamine “high” if the pattern fits and a “low” if the pattern is “off”). This effect delivers our “feelings” to a decision making center in the orbitofrontal cortex (OFC). In Lehrer’s synthesis the brain considers these often conflicting signals from its various parts until it forms a decision. Jeannie’s designation Brain Turmoil is apt: chapter 7 is entitled “The Brain Is an Argument”.

As I re-read Lehrer’s text trying to pinpoint what emotions are, I found his description too vague. Still I synthesized this working hypothesis: emotions are the self-communicated feelings, intuitions, or instincts formed by dopamine-mediated pattern detection centers in the brain. This gives a nice concrete notion of the nature of emotions that seems to fit well enough with the text and my experience. Does anyone know a better characterization of emotions?

Mistake Mystique

The message from the (sometimes excessively repetitive) middle part of the book is that both our “rational” and “emotional” brains can make serious mistakes. Lehrer recounts the emotional brain’s proclivity to find a pattern in any situation leading to grave errors whenever randomness is in play. For example, he explains the gamblers fallacy where one is rapturously deceived by occasional but completely random winnings leading to thoughts that “my turn has come” and the likelihood of bigger losses. He debunks the notion of streaks in sports citing the research of Gilovich, Vallone & Tversky that shows they are just random events that our brain misinterprets. There are more stories of this nature in the book. I had already encountered several from reading Fooled by Randomness by Nassim Nicholas Taleb which goes into great depth on this deficiency in the brain. Taleb details our weaknesses, but Lehrer also highlights some of our strengths and addresses how to make better decisions.

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