<P> Criticisms of this five - stage model of grief center mainly on a lack of empirical research and empirical evidence supporting the stages as described by Kübler - Ross and, to the contrary, empirical support for other modes of the expression of grief . Moreover, Kübler - Ross' model is the product of a particular culture at a particular time and might not be applicable to people of other cultures . These points have been made by many experts, (1) such as Professor Robert J. Kastenbaum (1932--2013) who was a recognized expert in gerontology, aging, and death; founder and editor of two academic journals in this area (International Journal of Aging and Human Development and Omega: Journal of Death and Dying); founder of the first university - based educational and research center on death and dying (Wayne State University, 1966); and author of several relevant books (e.g., The Psychology of Death (1972); Death, Society and Human Experience (1977); and On Our Way: The Final Passage Through Life and Death (2004)). In his writings, Kastenbaum raised the following points: </P> <Ul> <Li> The existence of these stages as such has not been demonstrated . </Li> <Li> No evidence has been presented that people actually do move from Stage 1 through Stage 5 . </Li> <Li> The limitations of the method have not been acknowledged . </Li> <Li> The line is blurred between description and prescription . </Li> <Li> The resources, pressures, and characteristics of the immediate environment, which can make a tremendous difference, are not taken into account . </Li> </Ul> <Li> The existence of these stages as such has not been demonstrated . </Li> <Li> No evidence has been presented that people actually do move from Stage 1 through Stage 5 . </Li>

Which stage of the kubler ross model is likely to be the most difficult