A Neuroscientist Reads… Robert Sapolsky’s Behave
When it comes to pop science, Robert Sapolsky is one of the best.
If there was ever a time to read such a mammoth of a book as Robert Sapolsky’s Behave, it’s during the coronavirus lockdown!
I first became aware of Sapolsky in a discussion with my supervisor many months ago. A behavioural neuroscientist himself, he commented on what an incredible career Sapolsky has had, mentioning he had written a number of popular science books. The name stuck, and a few months later, recognising Sapolsky’s name on my boyfriend’s bookshelf, I finally got hold of a copy of Behave.
This book is structured unlike any other I’ve read before. Focusing on how and why we make the actions and decisions we do, the first half of the book works backwards from the milliseconds before an action to the evolutionary changes that alter human behaviour. He discusses the neuromodulatory effects of the endocrine system, for example the context-dependent effects of sex hormones oestrogen and testosterone, through to the influence of neuroplasticity and our previous experiences. Neurodevelopment is then considered, in particular the changes that occur during adolescence that greatly shape our adult lives. He focuses on the slow maturation of the prefrontal cortex and how this can produce irrational and highly emotional behaviours in teenagers — I found it particularly interesting that adolescents actually do feel emotional pain more intensely than adults, due to the underdeveloped regulatory inputs of the prefrontal cortex. Finally, validation for all those years of teenage angst!
Going even further back, the book explores how maternal nutrition and our health in the womb can alter our behaviours, and how genetics have a huge impact on our actions and our susceptibility to mental illness. Finally, this part of the book discusses the evolution of behaviour, considering traditional human societies that have remained isolated from the modern world to draw parallels to our nomadic ancestors. Kin selection, altruism and how organisms have evolved to prefer close family members over strangers are all considered.
The second half of the book takes a more holistic approach, studying a specific aspect of human behaviour and diving deep into its neurobiological and evolutionary underpinnings. One such topic is the difference between “us” — those that we are related to or share a commonality — and “them” — everyone else! This section definitely leads to some uncomfortable truths. For example, in neuroimaging studies, the amygdala (the brain regions that controls fear and aggression) has been shown to be more reactive to faces of other races than those of our own. Although concerning, Sapolsky also demonstrates that simple techniques, for example focusing on the similarities you have with a person as opposed to their differences, can help to eliminate this response. Other chapters consider different societal views on hierarchy, obedience and individualism versus collectivism. It was very interesting to learn that these differences are not only cultural, but there are also genetic and neurological influences. The final chapter, simply named ‘War and Peace’, details the enormous capacity of humans to inflict pain and suffering on those we consider different. But it also highlights the humanity that draws us together — the trench warfare stories of Christmas ceasefires, and even soldiers deliberately firing over the heads of their enemies, were incredibly humbling.
Reading this book as a neuroscientist, the thought that kept coming back to me was that of the incredible knowledge and insight of the author. As mentioned before, Robert Sapolsky is a giant in the field of behavioural neuroscience. Born in 1957, he undertook a BA in Biological Anthropology from Harvard, going on to complete his PhD in Neuroendocrinology from Rockefeller University in New York. If you’re wondering what these two fields entail, Behave does a very good job of summing them up! Sapolsky’s research has focused on the social structure of baboons in the wild, and how this is influenced by stress hormones. He is currently a professor of biology and neuroscience at Stanford University, as well as being a research associate at the National Museums of Kenya. Behave is far from his first foray into pop science — Sapolsky has also written several other books, focusing on stress, neuroscience and animal behaviour. His research background has also made him a prominent public figure in the discussion around mental health and the evolution of human relationships.
This wealth of knowledge and research expertise makes Sapolsky the perfect guide for the complex world of human behaviour. Drawing on his extensive knowledge of animal behaviour, he helps us to make comparisons between different species and highlight the uniqueness of some human actions. For example, in the chapter focusing on the factors that influence our actions hours and days before they occur, different mating paradigms are discussed. Examples are given of monogamous prairie roles, who pair for life, and polyamorous montane voles. Under the framework of game theory, Sapolsky discusses the different tactics species have evolved in order to optimise mating behaviour. In general, the rest of the animal kingdom also fall into one of these two dichotomies. And as soap operas and reality TV show us, humans, however, do not. Similarly, the social structures of human civilisations are not just based on strength, being prosocial or mating capability. Uniquely, humans have created the abstract concept of socioeconomic status to enforce hierarchical societies, as well as inventing religion, politics and social norms to create structure based on our own personal biases and morals. All of which are, of course, influenced by the environment we are in. Sapolsky’s ability to concisely explain neurobiology, genetics and anthropology in such broad contexts is truly aspirational for any science writer.
Moreover, his book is incredibly well researched. Although it is clear that Sapolsky is an expert on many of the areas covered in this book, you’d have thought it impossible for him to so thoroughly cover such a broad range of neuroscience topics as there are in Behave. Just taking the topic I know best — depression, its causes and its treatments — he describes it as if he was someone who had been working in the field for decades. Not only does he highlight some of the key theories behind the causes of depression, as well as the genetic susceptibility of individuals, but he has also picked out the key literature from an enormous field, even being aware of controversies surrounding key papers. Seminal studies and influential individuals are discussed throughout the book. This is not insight one has after a quick literature search; these topic areas have clearly been studied intently. And although some of the examples used and analogies drawn are well-known to those who have a background in neuroscience, if I can ever write about my field half as well as Sapolsky does, I’ll be thrilled!
But that’s not to say this book is only for neuroscientists. There are three brilliant appendices that explain the key concepts of neuroscience, endocrinology and basic biochemistry, meaning this book is accessible even if you don’t have a background in life sciences. The first chapter is also great at introducing the key brain regions that will feature heavily in the book, explaining how they are connected and their respective functions extremely well. I’ll admit, I never really understood the amygdala and its connectivity until reading Sapolsky’s explanation. And it’s not a memory test — throughout the book, there are regular reminders of what each brain region does and how it is linked to the behaviour being discussed.
Behave also has a section for pretty much any interest. Obviously, neuroscience and basic human biology feature heavily, but genetics, evolution and zoology are also discussed extensively. The later sections would in fact be more familiar to social scientists, anthropologists or even historians, with lengthy discussions of philosophy and politics, all in the context of human behaviour. All this is to say that, even if you’re a neuroscience novice, you will be able to understand and enjoy this book.
So, how to sum up such a long, detailed and fascinating book? Well, it’s certainly not light bedtime reading — it’s critical to take your time reading Behave to really understand the concepts and their implications for society as a whole. Although at first glance it may seem intimidating, I really believe that anyone with an interest in human behaviour would love this book, regardless of their background. But with such an expert as a narrator, I’d expect nothing less. Echoing the words of famed neurologist Oliver Sachs, Sapolsky truly is “one of the best scientist-writers of our time”.
