The primary takeaway from the first 10 chapters is that determinism leaves no room for the existence of free will. Unpredictability is explained through chaoticism and emergent complexity, both of which are deterministic, while subatomic indeterminism is incapable of impacting behavior. The second half of the book will focus on the real-world consequences of accepting that there is no free will.

Sapolsky explores the common fear that a lack of belief in free will could cause antisocial behavior. He cites studies manipulating test subjects before testing various factors. Subjects primed for disbelief in free will have shown “less intentionality,” a weaker sense of agency, and increased antisocial behavior to a mild degree for a short time—“more amok-ish than amok” (250). To examine the impact of widespread disbelief in free will, Sapolsky discusses atheism versus the belief in moralizing gods. Such gods appeared in advancing civilizations with growing populations and were invoked to maintain social order. Atheism is stigmatized throughout the world, including in the US, where atheists experience more prejudice than any other social group.