The book focuses on the developmental analysis of brain-culture-environment dynamics and argues that this dynamic is interactive and reciprocal. Brain and culture co-determine each other. As a whole, this book refutes any unidirectional conception of the brain-culture dynamic. Each is influenced by and modifies the other. To capture the ubiquitous reach and significance of the mutually dependent brain-culture system, the metaphor of biocultural co-constructivism is invoked. Distinguished researchers from cognitive neuroscience, cognitive psychology, and developmental psychology review the evidence in their respective fields. A special focus of the book is its coverage of the entire human lifespan from infancy to old age. • Shows that throughout life, culture/environment and brain influence and modify each other • Shows that the brain is not an autonomous agent, but also a dependent variable that is co-constructed by culture and other aspects of the environment • The power of brain and cultural plasticity in co-shaping human behavior begins at conception and continues into old age