Fredrickson, B. L., & Losada, M. F. (2005). Positive affect and the complex dynamics of human flourishing. American psychologist, 60(7), 678.

The hypothesis tested in this article was motivated, in part, by the nonlinear dynamic model introduced in Losada (1999) and advanced in Losada and Heaphy (2004) and herein (Fredrickson & Losada, 2005). This model has since been called into question (Brown, Sokal, & Friedman, 2013). Losada has chosen not to defend his nonlinear dynamic model …

Fredrickson, B. L. (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions.

In this article, the author describes a new theoretical perspective on positive emotions and situates this in perspective within the emerging field of positive psychology. The broaden-and-build theory posits that experience of positive emotions broaden people’s momentary thought–action repertoires, which in turn serves to build their enduring personal resources, ranging from physical and intellectual resources …