The Domesticated Brain by Bruce Hood
Summary
Bruce Hood explores how the human brain has evolved, biologically and socially, in response to living in increasingly complex social environments. He argues that our brains have effectively been domesticated, much like wolves evolved into dogs. The book traverses genetics, anthropology, child development, and social psychology to explore the domesticated nature of modern humans.
As the wolf became the dog, the hunter became Homo domesticatedus. And if Hood is right, our hunter forebears on the African plains were not only tougher than us, but smarter too.
Key Insights
- Domestication is marked by physical and behavioural traits — Darwin noted that domesticated animals (including humans) tend to have droopy ears, smaller brains, and less aggression.
- Human brains are smaller than they were 20,000 years ago, possibly due to reduced physical demands and social collaboration.
- Wolves try to solve problems independently, while dogs look to humans — evidence of domestication.
- Epigenetics shows how the environment shapes gene expression, reinforcing our adaptability.
- Despite being only 1/50th of our body weight, the brain consumes 20% of our energy.
- Our large brains and upright walking create childbirth challenges, leading to human infants being born underdeveloped.
- Humans are dependent for longer than any other species — sometimes up to 25% of our lifespan.
- Social status and belonging are deeply embedded in brain function. Loneliness reduces immune function and increases disease risk.
- Children are egocentric until around age three, and morality evolves with social context.
- The marshmallow test shows that trust, not just self-control, predicts delayed gratification.
- Human fairness is deep-rooted — we punish freeloaders even at our own cost.
- The endowment effect causes us to irrationally overvalue things we own.
- Social exclusion is experienced as physical pain; conformity and belonging are critical.
- Engaging, accessible explanations of complex neuroscience.
- Excellent interdisciplinary approach — connecting brain function with real-world behaviours.
- Strong use of empirical evidence, including famous experiments like the marshmallow test.
Strengths
- Engaging, accessible explanations of complex neuroscience.
- Excellent interdisciplinary approach — connecting brain function with real-world behaviours.
- Strong use of empirical evidence, including famous experiments like the marshmallow test.
Weaknesses
- The book sometimes skims through evolutionary claims without deep engagement.
- Some examples may feel anecdotal or culturally specific (e.g., references to Chinese “Little Emperors”).
Reflections
This book reinforced the idea that our brains evolved more to deal with each other than with the external environment. Intelligence, empathy, and even morality are presented as adaptations for social living. Hood challenges the myth of the “rational individual,” showing how much of what we do is shaped by our need to belong and conform. The insight that loneliness can be as dangerous as smoking is particularly memorable.
Conclusion
The Domesticated Brain is a fascinating, readable account of how deeply social we are, right down to our neural wiring. Hood makes a compelling case that our brains are built not just to survive, but to coexist.
Book Details
Title: The Domesticated Brain
Author: Bruce Hood
Publication Year: 2014
Genre: Neuroscience
Reference: Calandra Vol. 4 p. 31
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