psychohistory is a separate field of scholarly inquiry with its own particular methods, objectives and theories, which set it apart from conventional historical analysis and anthropology. Some historians, social scientists and anthropologists have, however, argued that their disciplines already describe psychological motivation and that psychohistory is not, therefore, a separate subject. Others regard it as an undisciplined field of study, due to its emphasis given to speculation on the psychological motivations of people in history. Doubt has also been cast on the viability of the application of post-mortem psychoanalysis by Freud's followers. Psychohistorians maintain that the difference is one of emphasis and that, in conventional study, narrative and description are central, while psychological motivation is hardly touched upon. Psychohistorians accuse most anthropologists and ethnologists of being apologists for incest, infanticide, cannibalism and child sacrifice. They maintain that what constitutes child abuse is a matter of objective fact, and that some of the practices which mainstream anthropologists apologize for (e.g., sacrificial rituals) may result in psychosis, dissociation and magical thinking. Psychogenic mode Lloyd deMause has described a system of psychogenic modes (see below) which describe the range of styles of parenting he has observed historically and across cultures. Psychohistorians have written much about changes in the human psyche through history; changes that they believe were produced by parents, and especially the mothers' increasing capacity to empathize with their children. Due to these changes in the course of history, different psychoclasses (or psychogenic modes) emerged. A psychoclass is a type of mentality that results from, and is associated with, a particular childrearing style, and in its turn influences the method of childrearing of the next generations. According to psychohistory theory, regardless of the changes in the environment, it is only when changes in childhood occur and new psychoclasses evolve that societies begin to progress. The major psychogenic modes described by deMause are: Psychohistorians maintain that the five modes of abusive childrearing (excluding the "helping mode") are related to psychiatric disorders from psychoses to neuroses. The chart below shows the dates at which these modes are believed to have evolved in the most advanced nations, based on contemporary accounts from historical records. A black-and-white version of the chart appears in Foundations of Psychohistory. The y-axis on the above chart serves as an indicator of the new stage and not a measurement of the stage's size or relation to the x-axis. The timeline does