SENSUS VITAE
From stress in a single cell to the question of why we act as we do.
Robert Morris Sapolsky is a neuroendocrinologist, primatologist and writer on the science of behaviour. His work connects biology, neuroscience and behavioural research: from stress physiology and the brain to social relationships and the causes of human actions.
His scientific career brings together laboratory research and field observation. Trained in biological anthropology and neuroendocrinology, he spent many years studying wild baboons in Kenya, examining how social environments, hierarchies and relationships relate to stress and physiology.
One central question in his early work can be put simply: why can a physiological response that helps an organism survive a brief danger contribute to health problems when activated repeatedly or for too long?
That question offers a route from stress physiology to a broader problem: why do we behave as we do? The aim is to understand how biology and social history interact.
In his later books, he examines behaviour at several levels: brain processes immediately before an action, hormones, development, previous experience, social environments, culture and evolutionary history.
In Determined, Sapolsky takes his most controversial step: he defends a deterministic position and challenges traditional notions of free will. He explores what this would mean for responsibility, punishment and morality. This is the author's argument, not an established scientific consensus; its premises and implications remain subjects of scientific and philosophical debate.
Five books that progressively widen the question of behaviour. This is an editorial reading route, not a strict research chronology: Sapolsky’s laboratory and fieldwork developed alongside one another.
Stress and the body
Robert Sapolsky
The stress response mobilises the body during acute danger. Sapolsky explains why chronic activation, including in response to psychological and social stressors, can increase vulnerability to illness. The book moves from physiological mechanisms to the question of how we live with stress.
18 chapters
Hormones and behaviour
Robert Sapolsky
A collection of essays on the connections between biology, hormones, behaviour and human culture. Sapolsky explores the pitfalls of simple biological explanations: hormonal effects need to be understood in context and in relation to experience, not reduced to the claim that testosterone causes aggression.
1 of 17 chapters is available. Further chapters will be added as they are prepared.
The social lives of primates
Robert Sapolsky
A personal account of fieldwork with baboons in Africa. Observations of hierarchy, social relationships, stress and everyday primate behaviour sit alongside the researcher's own experiences. The book provides context for how life in the field shaped his scientific questions.
Why do we act as we do?
Robert Sapolsky
Sapolsky works backwards in time from an action. What happened in the brain moments before it? What roles did hormones, development and earlier experience play? How do social environments, culture and evolutionary history fit in? Behaviour emerges from the interaction of these levels, rather than a single cause.
Could we have acted otherwise?
Robert Sapolsky
From explaining the causes of behaviour, Sapolsky turns to free will. He advances a strongly deterministic argument and explores its implications for responsibility and punishment. This is his argued position; free will, determinism and moral responsibility remain subjects of scientific and philosophical debate.
The reading project for Why Zebras Don’t Get Ulcers is fully available here: all 18 chapter summaries, key concepts and questions for reflection. The first chapter of The Trouble with Testosterone is also available; its remaining 16 chapters and materials for the other three books are in preparation.
Read all 18 chaptersReturn to the chapter questions to connect the book’s ideas with your own observations and check your understanding.
Explore the chapter questions