The critical positivity ratio (also known as the Losada ratio or the Losada line) is a largely discredited concept in positive psychology positing an exact ratio of positive to negative emotions which distinguishes "flourishing" people from "languishing" people. The ratio was proposed by Marcial Losada and psychologist Barbara Fredrickson, who identified a ratio of positive to negative affect of exactly 2.9013 as separating flourishing from languishing individuals in a 2005 paper in "American Psychologist". The concept of a critical positivity ratio was widely embraced by both academic psychologists and the lay public; Fredrickson and Losada's paper was cited nearly 1,000 times, and Fredrickson wrote a popular book expounding the concept of "the 3-to-1 ratio that will change your life". Fredrickson wrote: "Just as zero degrees Celsius is a special number in thermodynamics, the 3-to-1 positivity ratio may well be a magic number in human psychology."