- Hemispheric lateralization
- The concept that the two hemispheres of the brain have different core competencies: the right hemisphere handles complex, holistic, meaning-oriented processing (the 'why'), while the left hemisphere handles analytical, linear, solution-oriented tasks (the 'how').
- Arrival fallacy
- A behavioural science term for the mistaken belief that reaching a goal will produce lasting satisfaction or a sense of worthiness; in practice the feeling never arrives, as described by Arthur Brooks and the gold medalist syndrome.
- Coherence (meaning)
- One of Michael Steger's three components of meaning: having a satisfying answer to why things happen the way they do in your life, which provides a sense of agency and pattern in the world.
- Simulacrum
- A copy or representation of something without the substance of the original; Arthur Brooks used it to describe online interactions that mimic real human connection while lacking its neurobiological and emotional depth.
- Default mode network
- A set of brain structures active during mind-wandering and inward reflection; Arthur Brooks cited it as the neural substrate for meaning-making that is suppressed by constant digital stimulation.
- Atelic
- Lacking a telos (external goal or endpoint); used by Arthur Brooks to describe activities or friendships that are valuable in themselves rather than as means to an end. Contrasted with 'telic'.
- Aporia
- An ancient Greek concept of sitting in a state of productive puzzlement over questions that cannot be answered; Arthur Brooks cited it as the philosophical practice underlying Zen koans and meaningful late-night philosophical conversations.
- Oxytocin
- A bonding neuropeptide released during in-person eye contact and shared meals; Arthur Brooks noted it flows during face-to-face interaction but is not triggered through Zoom screens.
- Scientism
- The cultural conceit that every problem is a complicated problem solvable through scientific or technological means; Arthur Brooks used it to describe the West's wrong turn in treating complex human problems as engineering challenges.
- Dorsal anterior cingulate cortex
- A region of the limbic system that is highly active during social exclusion and loss; Arthur Brooks described it as the neural origin of pain avoidance that motivates much human behaviour.
- Antimemetic
- Actively resisted in social transmission — the opposite of going viral; Chris Williamson used it to describe the arrival fallacy, which people intuitively refuse to share or accept because it threatens their motivational framework.
- Striver
- Arthur Brooks's term for high-achieving, perpetually driven individuals who are often motivated by a childhood belief that love must be earned through accomplishment, and who use success as an anesthetic for internal discomfort.
- Fugue state
- A dissociative psychological state in which a person becomes confused between their inner self-referential experience and their outward awareness of the world; Arthur Brooks used it to illustrate what happens when the 'me self' and 'I self' become conflated.
- Diotima of Mantinea
- A prophetess consulted by Socrates, described in Plato's Symposium, who explained a 'ladder of love' ascending from romantic attraction toward the divine — cited by Arthur Brooks as the philosophical foundation of the ladder of love.
- Teleological
- Goal-directed or oriented toward a final end; Arthur Brooks described himself as a teleological individual who finds aimless cruises depressing because they lack a destination.
- Acedia
- Sloth, torpor, or listless inactivity; referenced by philosopher Josef Pieper as distinct from genuine leisure, which Arthur Brooks contrasted with productive, value-creating non-work activities.
- Macronutrients of happiness
- Arthur Brooks's framework dividing happiness into three essential components: enjoyment (pleasure + people + memory), satisfaction (achieving goals through struggle), and meaning (coherence, purpose, significance).
- Catecholamines
- A class of neurotransmitters including dopamine, norepinephrine, and epinephrine; Arthur Brooks mentioned them as part of the neurochemical sequence activated when falling in love.
- Vasopressin
- A neuropeptide involved in bonding and attachment; Arthur Brooks cited it alongside oxytocin as part of the neurochemistry of long-term romantic love.
- Pathos
- A quality that evokes deep feeling, pity, or emotional understanding; Arthur Brooks used it to describe the charged moment when a wealthy financier articulated for the first time that he thought wealth would finally make his wife truly love him.