Glossary of decision-making & cognitive science

The LifeByLogic Glossary is the encyclopedia layer of an evidence-based publication of decision-support tools. Each entry defines a term used across our tools and methodology pages, anchors it to its peer-reviewed origin, surfaces common misconceptions, and explains how the concept appears in our measurement work. Entries are written for the general reader; technical depth is preserved in the cited primary sources.

The 22 entries below are organized by the lab cell where each term most often surfaces. Many terms cross labs; the grouping reflects primary association, not exclusive ownership.

• Brain age — estimated biological age of the brain relative to chronological age
• Chronotype — individual circadian preference (lark, owl, intermediate)
• Cognitive reserve — resilience of cognitive function against brain pathology
• Sleep cycle (90-minute) — the ultradian NREM–REM architecture of sleep
• Neuroplasticity — the brain's capacity to reorganize structure and function

• Cognitive bias — systematic deviation from rational judgment
• Anchoring effect — estimates pulled toward irrelevant numerical primes
• Confirmation bias — preference for information that confirms prior beliefs
• Bias blind spot — seeing bias in others while missing it in oneself
• Heuristic — mental shortcut for judgment under uncertainty

• Sunk cost — past expenditure that should not influence current choices
• Opportunity cost — the value of the best alternative not chosen
• Stay-vs-go decision — structured framework for voluntary departure choices
• Decision hygiene — practices that reduce noise in judgment

• Eudaimonia — Aristotelian concept of human flourishing
• Flourishing — multidimensional well-being across life domains
• Subjective well-being — self-reported life evaluation and emotional state
• Life satisfaction — cognitive evaluation of one's life as a whole

• Decision support system — structured tool aiding human judgment
• Self-report (in research) — data collected from participants' own accounts
• Validated instrument — measurement tool with established psychometric properties
• Effect size — magnitude of a relationship or difference

Each entry is written by Abiot Y. Derbie, PhD. Entries follow a consistent seven-section structure: canonical 50-word definition, conceptual origin, research evidence, common misconceptions, how LifeByLogic measures the construct, related terms, and selected primary references. Source citations are drawn from peer-reviewed primary literature. See the editorial policy for our sourcing and review standards.