Summary
Hands down one of the best books I have ever read. I very very strongly recommend picking up a copy. Robert Sapolsky is one of the most knowledgeable people on the topic of human behavior and this book is a tour de force display of that knowledge. I feel this book should be read in full and I don't do it justice when summarizing...
But here goes:
Human Behavior is a product of past influences. Past influences can stretch very far into the past, eventually thinking about the earliest living cells on Earth all the way to the most recent past, i.e. what happened in the last seconds leading up to a specific decision or behavior...
The crux is, that all of these influences are summed up within our brains to finally produce human behavior. And if we really want to understand human behavior and all it's nuances, we have to look at all the variables and how they play together. Which in itself explains how human behavior can be so incredibly complex, nuanced and faceted.
It has to be, because it's the product of the interplay of the forces of evolution, gene-expression, pre-natal environments, early childhood experiences, life long learnings, culture, current physiological state (hungry vs. not hungry, do you have a brain tumor, are you aroused, when was the last time you had sex etc.), to questions such as what is your hormonal state, is there adrenaline in your blood right now, what were you thinking about before, how rested are you etc.
And somehow all of this combines into one thing – the moment to moment things that you do.
Sapolsky dives into this whole mess, carefully dissecting it, step by step. All the while looking at lots of examples and detailing what we know (and what we are still struggling to understand) about how this thing – our brain – works to produce our day to day decisions.
Along that journey he explores the ramifications this kind of thinking opens up for concepts such as the morality and accountability for our actions, and how neuroscience will eventually influence law and our concepts of "guilt". He also tackles the idea of free will and why that concept makes less and less sense, the more we actually learn and understand about the brain.
Seriously. This book is good. Pick up a copy and read it cover to cover.
It is connected in spirit to other books such as The Selfish Gene, The Vital Question, From Bacteria to Bach and Back or The Brain.
Robert Sapolsky also has an epic lecture series with similar content to this book online on Youtube.
Detailed Notes
Sadly, I've read this book at a time where I didn't yet write detailed booknotes. But it is one of those books that were so incredibly good that I am going to re-read it more than once in the future. So there will be detailed notes here.