ABSTRACT
Variability in performance is ubiquitous to the human condition, and more broadly, to all life. It represents both the basis and the consequence of evolution-our understanding of how and why evolution occurs dates back to Darwin’s original account of the role of performance variability in the emergence of species: descent with modification. Performance variability is manifest in the functioning of all levels of human organization, from the molecular to complex sociotechnical systems. All domains of human science are grounded in the investigation of performance variability. In practical terms, analysis of performance variability leads to our understanding of the distribution of human populations and cultures across the planet and of the relative success or failure of learning and education, of social relationships, of health status and care, of athletic competition, of hiring and promotion, of organizational and institutional effectiveness and productivity, of community and societal functioning, of financial markets, and of entire state, nation, or economic systems.
