Lisa Feldman Barrett opens with her field-challenging thesis: emotions are actively constructed by the brain based on prior experience and context, rather than being universal, fixed reactions triggered automatically by specific circumstances, as more traditional emotion theory has long assumed.

Why this constructionist thesis challenges traditional emotion theory:

• Traditional emotion theory has often assumed specific emotions correspond to universal, biologically fixed patterns recognizable across all cultures and contexts
• Barrett's extensive neuroscience research instead suggests the brain actively constructs specific emotional experiences based on prior learning and immediate context, rather than triggering a fixed, universal response
• This challenging thesis has significant implications for how emotions should be understood, taught, and even treated clinically, motivating the book's subsequent detailed examination

This opening establishes the book's field-challenging central thesis, providing the foundation for its subsequent detailed neuroscientific examination of how emotions are actually constructed.