The persistence of wishful thinking.

Comments on the article by Fredrickson and Losada (see record 2005-11834-001). Recently the current authors (Brown, Sokal, & Friedman, 2013) debunked the widely cited claim made by Fredrickson and Losada (2005) that their use of a mathematical model drawn from nonlinear dynamics (namely, the Lorenz equations from fluid dynamics) provided theoretical support for the existence of a pair of critical positivity-ratio values (2.9013 and 11.6346) such that individuals whose ratios fall between these values will "flourish," whereas people whose ratios lie outside this ideal range will "languish." For lack of space in our previous article, we refrained from addressing, except in passing, the question of whether there might be empirical evidence for the existence of one or more critical positivity ratios ("tipping points"). In response to our critique, Fredrickson and Losada (2013) withdrew their nonlinear dynamics model, but Fredrickson (December December 2013) reaffirmed some claims concerning positivity ratios on the basis of empirical studies. We would therefore like to comment briefly on these claims and the alleged supporting evidence.