Behave: the biology of humans at our best and worst - book overview

I picked this book up from the local library and am glad I chanced upon it.

Behave: the biology of humans at our best and worst by Robert M. Sapolsky, published 2017 by Penguin. 

Sapolsky presents excerpts from the book on a recent TedTalk. 

This book tries to and mostly succeeds in bringing together, the many threads of neurobiological, developmental, along with the evolutionary, and  social and cultural contributions to how we behave.

The book is pitched at interested lay people, but requires background in human biology to understand. 

The 3 appendices provided are therefore extremely useful overviews of neuroscience (i.e. how the brain works); endocrinology (i.e. the contribution of hormones and biochemical) and proteins (i.e. the genetics basis of life).

The book also has extensive notes for the keen to follow up (50 pages) and a thorough index.

There are 17 chapters with short introduction and epilogue bracketing the content.

The book begins with a behaviour, then proceeds to uncover, over time, layer by layer, the many influences that allow the said behaviour to occur.

The first 2 chapters focus on the neurobiology and biochemistry which drives behaviour. Appendix 1, covering the basics of neurobiology, is recommended as a prerequisite. The three chapters cover the brain areas relevant to understanding behaviour. The amygdala which is where reward, anticipation arise; the role of dopamine; and the frontal lobes contribution to regulation and restraint of behaviours.

Then follow 3 chapters which overlap between physical neurobiology and the biochemical interactions which contribute to behaviour. In particular, details on testetorone (on aggression), oxytoxin and vasopressin (on the mother-infant bond), adaptive female aggression through estrogen, progesterone and oxytoxine, the effects of sustained stress and the caveat that hormones do not determine, command or cause behaviours but make us more sensitive to triggers from emotionally charged behaviours. The effects of these hormones on memory and discussion on neuroplasticity are also included. Chapter 6 provides application of the precepts from the previous chapters by exploring and discussing the adolescent brain – ‘or dude, where is my frontal cortex?’

Then follow 3 chapters focusing on human development. Summarising the various behaviours’ development from birth and the genetic/ epigenetic causes of some of these behaviours. Also the contribution of mother’s behaviours while baby is in the womb and the wider social issues which cause behaviours which are distinct in various populations. Chapter 8 has a good overview of epigenetics and argues that genes are not autonomous. Instead, they are regulated by the wider environment. Epigenetics can allow environmental effects to be lifelong or even across generations. So it is now not so much important what your genetical heritage might be but the environment in which those genes find themselves and how many other environmental factors contribute to how genes manifest, or remain dormant.

Chapter 9 synthesises the biological with aspects of the social-cultural. For example, the role of culture in contributing to why there is a gender gap in mathemathics testing. There is overview of the salient foundations of social theories, including collectivist vs individualist cultures; pastoralism (e.g. what agriculture has contributed); stratified vs egalitarian cultures; the effects of population size, density and heteriogeneity; and origins of religion and war.

Evolution's contribution is then discussed in the next three chapters. The premise is that evolution can shape behaviour, but with caveats. The usual foundations of evolution are discussed, including why there is reciprocal altruism, as it does not favour genetical transfer of the altruistic individual. The nuances of selection are proposed and critiqued – as in individual, group, kin selection etc.  In short, brain neurobiology, genes, hormones, social contributions etc.  provide not so much causes as propensities, potentials, vulnerabilities, predispositions etc.

Chapter 11 provides a good overview of why we are ‘tribal’ and why it we are drawn to ‘us vs them’ reactions. Discussions follow on the contribution of this concept to a whole host of human responses. Chapter 12 follows with extension of chapter 11 with discussion on the social basis of hierarchy, obedience and resistance. Why we crave status, its roots in biology and the social and cultural bases that support and enhance status. This chapter covers much ground. Importantly, the ways we make decisions are founded in our biology (i.e. how we make decisions, our approaches to reflective thought and how we resolve cognitive dissonance). Our social systems have ameliorated some of the predisposition to just look after ourselves and those close to us. For instance, we invented democracy and social welfare. However, we are also conformists and this may lead us to follow pathways which disadvantage ‘the other’.

The implications on behaviour are then presented in a couple of chapters. Chapter 13 summarises morality and ethics and how they contribute. Chapter 14 is on empathy, why do we feel the pain of others? And especially, why are we neurobiologically primed to have empathy.

Chapter 15 follows up behaviours at the other end of the continuum from empathy. Why do we kill? How do we circumvent the inner biological and cultural reinforcements of disgust etc. to kill others?

Chapter 16 is an interesting chapter which discusses whether we have free will. The criminal justice system is used as the basis for examples. In particular, how snippets of neuroscience research have been used, without deeper study of the actual implications. Hence, neurolaw, as an emergent science has to counter misconceptions and provide more studied responses.

The penultimate chapter ‘war and peace’ brings the various themes together. It presents the behaviours which have improved (i.e. we have mellowed and are less likely to go to war); discusses how to move forward and improve our behaviours as a species further; and summarises the best of humanity’s contributions.

In short, things are complicated. We may understand some of the underlying biological basis for behaviour but there are many contributing factors beyond the biological. There is never one factor or cause, but a multitude of interactions, concurrent shifts, biological and social coevolution etc. Understanding this means we need to read the literature critically and not just take things at face value.

All in, a really good synthesis, written in readable prose. Best read if you are interested in the topic as there is a lot to take in (over 600 pages including the appendices).