Robert M. Sapolsky (, is a distinguished primatologist working broadly in the life and social sciences to examine human behaviour, manifestations of which, he writes, belong to the nervous system and to sensory stimuli. Some of human behaviour is purely mechanical, with payoffs in dopamine, that ‘invidious, rapidly habituating reward.’ Other aspects are located at the intersection of nature and nurture, as with the plummeting U.S. crime rate in the 1990s, attributable in part to accessible abortion— for, as Sapolsky notes, nothing is quite so sure to lead to a life of crime as ‘being born to a mother who, if she could, would have chosen that you not be’. So the author attempts nothing less than a comprehensive account of human behaviour.


Along the way there are many counter-intuitive ideas. Empathy – feeling someone’s pain – is not as likely to lead to useful action as dispassionate sympathy, or ‘cold-blooded kindness’. Income inequality is concretely bad for the health of the poor. There is a well-established link between right wing authoritarianism and lower IQ. Genes are not destiny, and they are not in any simple sense ‘selfish’; humans haven’t evolved to be ‘selfish’ or ‘altruistic’ or anything else – we’ve evolved to be particular ways in particular settings. Testosterone, for example, does not cause aggression but amplifies pre-existing tendencies for or against it. The actions of such molecules in general ‘depend dramatically on context’. In general, if our worst behaviours are the product of our biology, so are our best ones. Throughout, Sapolsky insists on how much individual variability there is hidden beneath the statistical averages of studies, and how the explanation of nearly every human phenomenon is going to be ‘multi-factorial’.


This book is an awesome scholarly survey of all the determinant factors that, for better or worse, define human beings. Incidentally, one of Sapolsky’s strong conclusions from all this is that free will is an illusion. Whether you choose to read the arguments in favour of this conclusion isn’t up to you.


You may, or may not, enquire at your local library.  You may check if this new work of popular science is in stock by consulting the online catalogue at


800 pages in Bodley Head

First published 2017

ISBN  978-1847922168



portrait of Robert Sapolsky

Professor Robert Sapolsky

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