 Fredrickson has agreed that the mathematical modelling is "questionable", but stands by the more general idea that a high emotional positivity-to-negativity ratio is beneficial.The whole theory of the critical positivity ratio was discredited by Nicholas Brown, Alan Sokal, and Harris Friedman, in a 2013 article published in "American Psychologist", the same journal in which Fredrickson's original findings were published in 2005.Brown et al.